Supporting Information Selective Synthesis of xygen-containing Heterocycles via Tandem Reactions of 1,2-Allenic Ketones with Ethyl 4-Chloroacetoacetate Qiang Wang, a, b Zhouqing Xu b and Xuesen Fan a * a School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical dia and Reactions, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, P. R. China. b School of Physics-Chemistry, Henan Polytechnic University, Jiaozuo, Henan, 454003, P. R. China. E-mail: xuesen.fan@htu.cn; xuesen.fan@yahoo.com Table of Contents I. General experimental information P2 II. Experimental procedures and spectroscopic data P3-15 III. Copies of 1 H and 13 C NMR spectra of 3a-3s, 4a-4n, 4aa, 5a-5d and 6a P16-54 IV. X-ray crystal structures of 3f, (E)-4aa and 5c P55-57 V. References P58 1
I. General Experimental Information The 1 H, 13 C NMR spectra were recorded at 400 MHz or 100 MHz, respectively. Chemical shifts were reported in ppm from CDCl 3 as standard. Multiplicity was indicated as follows: s (singlet); d (doublet); t (triplet); q (quartet); m (multiplet); dd (doublet of doublets); td (triplet of doublets); qd (quartet of doublets); br s (broad singlet), etc. and coupling constants were given in Hz. The conversion of starting materials were monitored by thin layer chromatography (TLC) using silica gel plates (silica gel 60 F254 0.25 mm) and components were visualized by observation under UV light (254 and 365 nm). Mass spectra were obtained using a Waters Acquity SQ HPLC-mass spectrometer. High resolution mass spectra (HRMS) were performed on a time-of-flight (microtf) mass spectrometer. 2
II. Experimental Procedures and Spectroscopic Data 1-Aryl substituted allenic ketones were prepared through oxidation of the corresponding homopropargyl alcohols, 1 which were prepared through zinc promoted propargylation of aldehydes. 2 1,4-Disubsituted allenic ketones were prepared from 1-(triphenylphosphoranylidene)-2-propanone or 2- (triphenyl phosphoranylidene)acetophenone with phenylacetyl chloride based on a literature procedure. 3 1. Typical procedure for the preparation of ethyl 5-methyl-3-oxo-7-phenyl-2,3-dihydrooxepine-4- carboxylate (3a) To a flask containing 1-phenylbuta-2,3-dien-1-one (1a, 1 mmol) and ethyl 4-chloroacetoacetate (2, 1.2 mmol) in CH 3 CN (5 ml) were added anhydrous K 2 C 3 (1.0 mmol). The solution was stirred at room temperature for 1 h. The reaction then was quenched with aqueous NH 4 Cl and extracted with ethyl acetate (5 ml 3). The combined organic phases were dried, filtered and concentrated under vacuum. The residue was purified by column chromatography over silica gel using ethyl acetate/hexane (v/v = 1:10) as eluent to give 3a (68%). 3b-3s were obtained in a similar manner. C 2 Et Ethyl 5-methyl-3-oxo-7-phenyl-2,3-dihydrooxepine-4-carboxylate (3a) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.71 (d, J = 8.0 Hz, 2H), 7.40-7.46 (m, 3H), 6.02 (s, 1H), 4.69 (s, 2H), 4.34 (q, J = 7.6 Hz, 2H), 2.21 (s, 3H), 1.35 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.2, 167.7, 165.1, 149.4, 134.3, 133.4, 131.2, 128.7, 127.1, 106.9, 77.5, 61.5, 24.8, 14.2. MS(ESI): m/z 295.4 [M+Na] +. HRMS (ESI) Calcd for C 16 H 17 4 : [M+H] + 273.1127, found: 273.1137. Ethyl 5-methyl-3-oxo-7-p-tolyl-2,3-dihydrooxepine-4-carboxylate (3b) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.59 (d, J = 8.4 Hz, 2H), 7.21 (d, J = 7.6 Hz, 2H), C 2 Et 5.98 (s, 1H), 4.66 (s, 2H), 4.33 (q, J = 7.2 Hz, 2H), 2.38 (s, 3H), 2.19 (s, 3H), 1.34 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.2, 167.8, 165.4, 149.7, 141.9, 133.9, 130.6, 129.5, 127.2, 106.2, 77.5, 61.4, 24.8, 21.4, 14.1. HRMS (ESI) Calcd for C 17 H 19 4 : [M+H] + 287.1283, found: 287.1288. 3
Ethyl 7-(4-methoxyphenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate C 2 Et (3c) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.63 (d, J = 8.4 Hz, 2H), 6.89 (d, J = 8.4 Hz, 2H), 5.91 (s, 1H), 4.63 (s, 2H), 4.31 (q, J = 6.8 Hz, 2H), 3.82 (s, 3H), 2.18 (s, 3H), 1.32 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 186.9, 167.9, 165.3, 162.2, 150.2, 133.4, 129.0, 125.7, 114.1, 105.3, 77.4, 61.3, 55.4, 24.9, 14.1. HRMS (ESI) Calcd for C 17 H 19 5 : [M+H] + 303.1232, found: 303.1240. Ethyl 7-(4-fluorophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3d) F 1 H NMR (400 MHz, CDCl 3 ) δ: 7.67-7.70 (m, 2H), 7.06-7.10 (m, 2H), 5.94 (s, 1H), C 2 Et 4.66 (s, 2H), 4.32 (q, J = 7.2 Hz, 2H), 2.19 (s, 3H), 1.33 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.0, 167.6, 163.9, 163.3, 149.3, 134.3, 129.7, 129.6, 129.4, 129.3, 115.9, 115.7, 106.6, 77.5, 61.5, 24.8, 14.1. HRMS (ESI) Calcd for C 16 H 16 F 4 : [M+H] + 291.1033, found: 291.1039. Ethyl 7-(4-chlorophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3e) Cl 1 H NMR (400 MHz, CDCl 3 ) δ: 7.62 (d, J = 8.4 Hz, 2H), 7.36 (d, J = 8.4 Hz, 2H), 5.98 C 2 Et (s, 1H), 4.65 (s, 2H), 4.32 (q, J = 7.2 Hz, 2H), 2.19 (s, 3H), 1.33 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.1, 167.5, 163.6, 148.9, 137.3, 134.6, 131.9, 128.9, 128.3, 107.1, 77.4, 61.5, 24.8, 14.1. MS(ESI): m/z 329.2, 329.5 [M+Na] +.HRMS (ESI) Calcd for C 16 H 16 Cl 4 : [M+H] + 307.0737, found: 307.0743. Br Ethyl 7-(4-bromophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3f) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.51-7.56 (m, 4H), 5.99 (s, 1H), 4.66 (s, 2H),, 4.32 (q, C 2 Et J = 6.8 Hz, 2H), 2.19 (s, 3H), 1.33 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.1, 167.5, 163.7, 149.0, 134.6, 132.3, 131.9, 128.5, 125.8, 107.1, 77.4, 61.5, 24.8, 14.2. MS(ESI): m/z 373.3, 375.4 [M+Na] +. HRMS (ESI) Calcd for C 16 H 16 Br 4 : [M+H] + 351.0232, found: 351.0239. F 3 C Ethyl 5-methyl-3-oxo-7-(4-(trifluoromethyl)phenyl)-2,3-dihydrooxepine-4- C 2 Et carboxylate (3g) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.80 (d, J = 8.4 Hz, 2H), 7.65 (d, J = 7.6 Hz, 2H), 6.07 4
(s, 1H), 4.68 (s, 2H), 4.33 (q, J = 7.2 Hz, 2H), 2.21 (s, 3H), 1.34 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.2, 167.3, 162.8, 148.4, 136.9, 135.3, 132.2, 127.1, 125.65, 125.61, 125.58, 108.5, 77.5, 24.7, 14.1. HRMS (ESI) Calcd for C 17 H 16 F 3 4 : [M+H] + 341.1001, found: 341.1011. F Ethyl 7-(3-fluorophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3h) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.47 (d, J = 8.0 Hz, 1H), 7.34-7.39 (m, 2H), 7.13 (t, J = C 2 Et 8.0 Hz, 1H), 6.00 (s, 1H), 4.65 (s, 2H), 4.32 (q, J = 7.6 Hz, 2H), 2.18 (s, 3H), 1.33 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.2, 167.4, 164.0, 163.2, 161.6, 148.7, 135.74, 135.66, 134.89, 130.33, 130.26, 122.57, 122.54, 117.98, 117.78, 113.9, 113.7, 107.7, 77.4, 61.5, 14.1. HRMS (ESI) Calcd for C 16 H 16 F 4 : [M+H] + 291.1033, found: 291.1037. Cl Ethyl 7-(3-chlorophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3i) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.66 (s, 1H), 7.57 (d, J = 7.6 Hz, 1H) 7.40 (d, J = 8.4 Hz, C 2 Et 1H), 7.33 (t, J = 8.0 Hz, 1H), 4.66 (s, 2H), 5.99 (s, 1H), 4.33 (q, J = 7.6 Hz, 2H), 2.19 (s, 3H), 1.34 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.2, 167.4, 163.01, 148.7, 135.3, 134.9, 134.8, 130.9, 129.9, 126.9, 125.0, 107.7, 77.5, 61.5, 24.7, 14.1. HRMS (ESI) Calcd for C 16 H 16 Cl 4 : [M+H] + 307.0737, found: 307.0741. Br Ethyl 7-(3-bromophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3j) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.82 (s, 1H), 7.62 (d, J = 7.6 Hz, 1H), 7.56 (d, J = 8.0 Hz, C 2 Et 1H), 7.28 (t, J = 7.6 Hz, 1H), 5.98 (s, 1H), 4.66 (s, 2H), 4.33 (q, J = 6.8 Hz, 2H), 2.19 (s, 3H), 1.34 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.2, 162.9, 148.6, 148.6, 135.5, 134.9, 133.8, 130.2, 129.9, 125.5, 122.9, 107.7, 77.5, 61.5, 24.7, 14.1. HRMS (ESI) Calcd for C 16 H 16 Br 4 : [M+H] + 351.0232, found: 351.0238. Ethyl 5-methyl-3-oxo-7-m-tolyl-2, 3-dihydrooxepine-4-carboxylate (3k) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.48-7.50 (m, 2H), 7.24-7.31 (m, 2H), 5.99 (s, 1H), 4.65 C 2 Et (s, 2H), 4.33 (q, J = 6.8 Hz, 2H), 2.38 (s, 3H), 2.19 (s, 3H), 1.34 (t, J = 6.8 Hz, 3H). 13 C 5
NMR (100 MHz, CDCl 3 ) δ: 187.2, 167.7, 165.3, 149.5, 138.4, 134.2, 133.4, 132.0, 128.6, 127.7, 124.3, 106.9, 77.5, 61.4, 24.8, 21.4, 14.1. HRMS (ESI) Calcd for C 17 H 19 4 : [M+H] + 287.1283, found: 287.1289. Ethyl 7-(3,4-dimethoxyphenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate C 2 Et (3l) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.33 (dd, J 1 = 2.0 Hz, J 2 = 10.4 Hz, 1H), 7.16 (d, J = 1.6 Hz, 1H), 6. 88 (d, J = 8.8 Hz, 1H), 5.92 (s, 1H), 4.67 (s, 2H), 4.33 (q, J = 7.2 Hz, 2H), 3.92 (s, 6H), 2.20 (s, 3H), 1.34 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 186.9, 167.8, 165.3, 151.9, 149.9, 148.9, 133.5, 125.9, 121.1, 110.9, 109.8, 105.5, 77.5, 65.9, 61.4, 24.9, 14.1. HRMS (ESI) Calcd for C 18 H 21 6 : [M+H] + 333.1338, found: 333.1343. Ethyl 7-(2-methoxyphenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3m) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.50-7.52 (m, 1H), 7.36-7.40 (m, 1H), 6.93-6.99 (m, 2H), C 2 Et 6.13 (s, 1H), 4.64 (s, 2H), 4.33 (q, J = 6.8 Hz, 2H), 3.87 (s, 3H), 2.16 (s, 3H), 1.34 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 188.5, 167.8, 163.1, 158.0, 149.4, 134.2, 132.0, 130.3, 123.4, 120.6, 112.3, 111.5, 77.5, 61.3, 55.8, 24.7, 14.1. HRMS (ESI) Calcd for C 17 H 19 5 : [M+H] + 303.1232, found: 303.1242. Ethyl 7-(2-fluorophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3n) F 1 H NMR (400 MHz, CDCl 3 ) δ: 7.58-7.62 (m, 1H), 7.36-7.39 (m, 1H), 7.15-7.19 (m, 1H), C 2 Et 7.07-7.12 (m, 1H), 6.08 (s, 1H), 4.65 (s, 2H), 4.32 (q, J = 6.8 Hz, 2H), 2.16 (s, 3H), 1.33 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.9, 167.5, 161.7, 159.8, 159.8, 159.2, 148.7, 134.9, 132.4, 132.3, 130.1, 124.4, 124.3, 122.2, 122.0, 116.6, 116.4, 112.4, 112.3, 77.5, 61.4, 24.7, 14.1. MS(ESI): m/z 313.6 [M+Na] +. HRMS (ESI) Calcd for C 16 H 16 F 4 : [M+H] + 291.1033, found: 291.1043. Cl Ethyl 7-(2-chlorophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3o) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.39-7.41 (m, 2H), 7.32-7.36 (m, 1H), 7.25-7.29 (m, C 2 Et 1H), 5.68 (s, 1H), 4.69 (s, 2H), 4.32 (q, J = 6.8 Hz, 2H), 2.14 (s, 3H), 1.33 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.5, 167.4, 148.3, 134.9, 134.1, 133.9, 131.6, 131.4, 130.4, 6
126.8, 112.0, 77.4, 61.5, 24.5, 14.1. HRMS (ESI) Calcd for C 16 H 16 Cl 4 : [M+H] + 307.0737, found: 307.0744. Br Ethyl 7-(2-bromophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3p) C 2 Et 1 H NMR (400 MHz, CDCl 3 ) δ: 7.57 (d, J = 7.6 Hz, 1H), 7.37 (dd, J 1 = 1.6 Hz, J 2 = 7.6 Hz, 1H), 7.29 (t, J = 7.2 Hz, 1H), 7.24 (dt, J 1 = 1.6 Hz, J 2 = 7.6 Hz, 1H), 5.61 (s, 1H), 4.69 (s, 2H), 4.29 (q, J = 7.2 Hz, 2H), 2.12 (s, 3H), 1.31 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.3, 167.4, 164.9, 148.3, 136.1, 134.9, 133.5, 131.7, 127.4, 123.1, 111.6, 77.6, 61.4, 30.8, 24.5, 14.1. HRMS (ESI) Calcd for C 16 H 16 Br 4 : [M+H] + 351.0232, found: 351.0243. Ethyl 5-methyl-7-(naphthalen-1-yl)-3-oxo-2,3-dihydrooxepine-4-carboxylate (3q) C 2 Et 1 H NMR (400 MHz, CDCl 3 ) δ: 8.05 (d, J = 8.4 Hz, 1H), 7.86-7.92 (m, 2H), 7.44-7.60 (m, 4H), 5.81 (s, 1H), 4.82 (s, 2H), 4.38 (q, J = 6.8 Hz, 2H), 2.21 (s, 3H), 1.38 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 186.7, 167.7, 166.5, 149.2, 134.4, 133.7, 132.7, 131.3, 131.1, 128.7, 128.6, 127.2, 126.3, 124.9, 124.9, 111.8, 77.5, 61.5, 24.8, 14.2. HRMS (ESI) Calcd for C 20 H 19 4 : [M+H] + 323.1283, found: 323.1291. Ethyl 7-benzyl-5-methyl-3-oxo-2,3-dihydrooxepine-4-carboxylate (3r) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.30-7.34 (m, 2H), 7.21-7.28 (m, 3H), 5.29 (s, 1H), C 2 Et 4.42 (s, 2H), 4.29 (q, J = 7.2 Hz, 2H), 3.56 (s, 2H), 2.03 (s, 3H), 1.31 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 187.0, 168.9, 167.6, 148.9, 136.2, 133.9, 128.9, 128.7, 127.1, 108.9, 77.1, 61.3, 42.1, 24.5, 14.1. HRMS (ESI) Calcd for C 17 H 19 4 : [M+H] + 287.1283, found: 287.1289. Ethyl 5-methyl-3-oxo-7-phenethyl-2,3-dihydrooxepine-4-carboxylate (3s) C 2 Et 1 H NMR (400 MHz, CDCl 3 ) δ: 7.25-7.29 (m, 2H), 7.13-7.20 (m, 3H), 5.19 (s, 1H), 4.41 (s, 2H), 4.28 (q, J = 7.2 Hz, 2H), 2.85 (t, J = 8.0 Hz, 2H), 2.57 (t, J = 7.6 Hz, 2H), 1.98 (s, 3H), 1.30 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 186.9, 169.5, 167.6, 149.2, 140.2, 133.6, 128.5, 128.3, 126.3, 108.6, 76.8, 61.3, 37.6, 33.4, 24.4, 14.1. HRMS (ESI) Calcd for C 18 H 21 4 : [M+H] + 301.1440, found: 301.1449. 7
2. Typical procedure for the preparation of ethyl 2,5-dimethyl-2-(2-oxo-2-phenylethyl)-7-phenyl benzo[d][1,3]dioxole-4-carboxylate (4a) To a flask containing 1-phenylbuta-2,3-dien-1-one (1a, 2.0 mmol) and ethyl 4-chloroacetoacetate (2, 1.0 mmol) in toluene (5 ml) were added anhydrous K 2 C 3 (2.5 mmol) and tetrabutyl ammonium bromide (0.05 mmol). The solution was stirred at room temperature for 1 h. The reaction then was quenched with aqueous NH 4 Cl and extracted with ethyl acetate (5 ml 3). The combined organic phases were dried, filtered and concentrated under vacuum. The residue was purified by column chromatography on silica gel eluenting with ethyl acetate/hexane (v/v: 1/10) to give 4a (62%). 4b-4n were obtained in a similar manner. Ethyl 2,5-dimethyl-2-(2-oxo-2-phenylethyl)-7-phenylbenzo[d][1,3]dioxole-4- C 2 Et carboxylate (4a) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.90 (d, J = 8.0 Hz, 2H), 7.62 (d, J = 7.2 Hz, 2H), 7.50 (t, J = 7.2 Hz, 1H), 7.30 (t, J = 7.2 Hz, 1H), 7.34-7.41 (m, 4H), 6.89 (s, 1H), 4.25-4.33 (m, 2H), 3.64 (d, J = 14.8 Hz, 1H), 3.63 (d, J = 14.8 Hz, 1H), 2.49 (s, 3H), 1.93 (s, 3H), 1.28 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 195.1, 165.4, 147.9, 142.8, 137.2, 135.1, 133.2, 131.6, 128.6, 128.5, 128.5, 127.9, 127.8, 124.4, 122.8, 117.8, 112.9, 60.7, 46.9, 24.8, 20.8,14.2. HRMS (ESI) Calcd for C 26 H 25 5 : [M+H] + 417.1702, found: 417.1711. F Ethyl 7-(4-fluorophenyl)-2-(2-(4-fluorophenyl)-2-oxoethyl)-2,5-dimethyl F C 2 Et benzo[d][1,3]dioxole-4-carboxylate (4b) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.88-7.92 (m, 2H), 7.56-7.59 (m, 2H), 6.98-7.07 (m, 4H), 6.81 (s, 1H), 4.30 (qd, J 1 = 1.6 Hz, J 2 = 7.6 Hz, 2H), 3.62 (d, J = 14.4 Hz, 1H), 3.55 (d, J = 14.4 Hz, 1H), 2.45 (s, 3H), 1.91 (s, 3H), 1.29 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.5, 167.1, 165.2, 164.6, 163.7, 161.2, 147.8, 142.5, 133.63, 133.60, 131.8, 131.4, 131.3, 131.04, 131.01, 129.7, 129.6, 123.4, 122.5, 117.7, 115.6, 115.55, 115.38, 115.33, 112.9, 60.8, 47.0, 24.8, 20.8, 14.1. HRMS (ESI) Calcd for C 26 H 23 F 2 5 : [M+H] + 453.1514, found: 453.1525. 8
Cl Ethyl 7-(4-chlorophenyl)-2-(2-(4-chlorophenyl)-2-oxoethyl)-2,5-dimethyl Cl benzo[d][1,3]dioxole-4-carboxylate (4c) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.78-7.80 (m, 2H), 7.51-7.54 (m, 2H), 7.28-7.34 C 2 Et (m, 4H), 6.82 (s, 1H), 4.30 (q, J = 7.6 Hz, 2H), 3.61 (d, J = 14.8 Hz, 1H), 3.54 (d, J = 14.0 Hz, 1H), 2.45 (s, 3H), 1.91 (s, 3H), 1.30 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.9, 165.12 147.8, 142.6, 139.8, 135.4, 133.9, 133.4, 131.9, 130.0, 129.1, 128.7, 123.1, 122.4, 117.7, 113.3, 60.8, 47.0, 24.9, 20.8, 14.2. HRMS (ESI) Calcd for C 26 H 23 Cl 2 5 : [M+H] + 485.0923, found: 485.0932. Br Ethyl 7-(4-bromophenyl)-2-(2-(4-bromophenyl)-2-oxoethyl)-2,5-dimethyl Br benzo[d][1,3]dioxole-4-carboxylate (4d) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.69 (d, J = 8.0 Hz, 2H), 7.42-7.48 (m, 6H), 6.80 C 2 Et (s, 1H), 4.28 (q, J = 6.8 Hz, 2H), 3.58 (d, J = 14.4 Hz, 1H), 3.51 (d, J = 14.4 Hz, 1H), 2.43 (s, 3H), 1.89 (s, 3H), 1.28 (t, J = 6.8 Hz, 3H). 13 C NMR (400 MHz, CDCl 3 ) δ: 194.1, 165.1, 147.8, 142.6, 135.8, 133.8, 131.9, 131.7, 131.7, 130.1, 129.4, 128.5, 123.1, 122.3, 122.2, 117.7, 113.3, 60.8, 47.0, 24.8, 20.8, 14.2. HRMS (ESI) Calcd for C 26 H 23 Br 2 5 : [M+H] + 572.9912, found: 572.9921. CF 3 Ethyl 2,5-dimethyl-2-(2-oxo-2-(4-(trifluoromethyl)phenyl)ethyl)-7-(4-(tri CF 3 fluoromethyl)phenyl)benzo[d][1,3]dioxole-4-carboxylate (4e) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.95 (d, J = 8.4 Hz, 2H), 7.68 (d, J = 8.0 Hz, 2H), C 2 Et 7.59 (t, J = 8.8 Hz, 4H), 6.85 (s, 1H), 4.29 (q, J = 6.8 Hz, 2H), 3.68 (d, J = 14.4 Hz, 1H), 3.60 (d, J = 14.4 Hz, 1H), 2.44 (s, 3H), 1.92 (s, 3H), 1.28 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 194.1, 165.0, 147.8, 142.9, 139.6, 138.5, 132.0, 128.9, 128.1, 125.5, 125.44, 125.41, 125.37, 125.3, 122.7, 122.67, 122.6, 117.8, 113.9, 60.9, 47.3, 24.9, 20.7, 14.4. HRMS (ESI) Calcd for C 28 H 23 F 6 5 : [M+H] + 553.1450, found: 553.1456. F Ethyl 7-(3-fluorophenyl)-2-(2-(3-fluorophenyl)-2-oxoethyl)-2,5-dimethyl F benzo[d][1,3] dioxole-4-carboxylate (4f) 1 H NMR (400 MHz, CDCl 3 ) δ: 1.30 (t, J = 7.6 Hz, 3H), 1.92 (s, 3H), 2.45 (s, C 2 Et 3H), 3.57 (d, J = 14.4 Hz, 1H), 3.63 (d, J = 14.4 Hz, 1H), 4.30 (qd, J 1 = 1.6 Hz, J 2 = 6.8 Hz, 2H), 6.85 9
(s, 1H), 6.97-7.01 (m, 1H), 7.16-7.21 (m, 1H), 7.29-7.35 (m, 3H), 7.39 (d, J = 7.6 Hz, 1H), 7.56-7.59 (m, 1H), 7.65 (d, J = 7.6 Hz, 1H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.8, 165.2, 164.0, 163.9, 161.6, 161.5, 147.9, 142.8, 139.2, 139.1, 137.1, 137.05, 131.9, 130.2, 130.1, 130.01, 129.9, 124.4, 124.39,123.48, 123.45, 123.0, 120.4, 120.2, 117.8, 115.3, 115.0, 114.88, 114.86, 114.7, 113.4, 60.8, 47.1, 24.9, 20.8, 14.1. HRMS (ESI) Calcd for C 26 H 23 F 2 5 : [M+H] + 453.1514, found: 453.1520. Ethyl 7-(3-chlorophenyl)-2-(2-(3-chlorophenyl)-2-oxoethyl)-2,5-dimethyl Cl Cl C 2 Et benzo[d][1,3]dioxole-4-carboxylate (4g) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.82-7.83 (m, 1H), 7.70-7.73 (m, 1H), 7.56-7.57 (m, 1H), 7.42-7.49 (m, 2H), 7.24-7.30 (m, 3H), 6.83 (s, 1H), 4.27-4.34 (m, 2H), 3.64 (d, J = 14.4 Hz, 1H), 3.57 (d, J = 14.4 Hz, 1H), 2.45 (s, 3H), 1.92 (s, 3H), 1.30 (t, J = 7.6 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.8, 165.1, 147.9, 142.7, 138.6, 136.7, 134.9, 134.4, 133.1, 131.9, 129.8, 129.7, 128,5, 127.9, 127.8, 126.7, 126.1, 122.8, 122.5, 117.8, 113.4, 60.8, 47.0, 24.9, 20.8,14.2. HRMS (ESI) Calcd for C 26 H 23 Cl 2 5 : [M+H] + 485.0923, found: 485.0929. Br Ethyl 7-(3-bromophenyl)-2-(2-(3-bromophenyl)-2-oxoethyl)-2,5-dimethyl Br benzo[d][1,3]dioxole-4-carboxylate (4h) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.99 (t, J = 2.0 Hz, 1H), 7.76-7.78 (m, 1H), 7.72 C 2 Et (t, J = 1.6 Hz, 1H), 7.59-7.62 (m, 1H), 7.51-7.54 (m, 1H), 7.42-7.45 (m, 1H), 7.22 (q, J = 7.6 Hz, 2H), 6.83 (d, J = 0.8 Hz, 1H), 4.28-4.34 (m, 2H), 3.62 (d, J = 14.4 Hz, 1H), 3.55 (d, J = 14.4 Hz, 1H), 2.46 (s, 3H), 1.92 (s, 3H), 1.30 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.8, 165.1, 147.9, 142.7, 138.8, 137.0, 136.1, 131.8, 131.4, 130.9, 130.6, 130.0, 127.1, 126.6, 122.9, 122.8, 122.7, 122.5, 117.8, 113.5, 60.9, 47.0, 24.9, 20.8, 14.2. HRMS (ESI) Calcd for C 26 H 23 Br 2 5 : [M+H] + 572.9912, found: 572.9919. Ethyl 2,5-dimethyl-2-(2-oxo-2-m-tolylethyl)-7-m-tolylbenzo[d][1,3]dioxole-4- carboxylate (4i) C 2 Et 1 H NMR (400 MHz, CDCl 3 ) δ: 7.72 (d, J = 6.8 Hz, 2H), 7.43 (d, J = 7.2 Hz, 2H), 7.33 (t, J = 7.6 Hz, 1H), 7.26 (t, J = 4.8 Hz, 2H), 7.13 (d, J = 7.2 Hz, 1H), 6.90 (d, J = 0.4 Hz, 1H), 10
4.27-4.35 (m, 2H), 3.67 (d, J = 14.4 Hz, 1H), 3.61 (d, J = 14.4 Hz, 1H), 2.50 (s, 3H), 2.35 (s, 3H), 2.33 (s, 3H), 1.95 (s, 3H), 1.30 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 195.4, 165.5, 148.0, 142.8, 138.3, 138.1, 137.3, 135.0, 134.0, 131.6, 129.1, 128.7, 128.5, 128.4, 125.9, 125.1, 124.6, 122.8, 117.8, 112.8, 60.7, 46.9, 24.8, 21.5, 21.2, 20.9, 14.2. HRMS (ESI) Calcd for C 28 H 29 5 : [M+H] + 445.2015, found: 445.2020. Ethyl 7-(4-methoxyphenyl)-2-(2-(4-methoxyphenyl)-2-oxoethyl)-2,5- dimethylbenzo[d][1,3]dioxole-4-carboxylate (4j) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.85-7.89 (m, 2H), 7.55-7.59 (m, 2H), 6.87- C 2 Et 6.91(m, 2H), 6.85 (s, 1H), 6.78-6.82 (m, 2H), 4.26-4.32 (m, 2H), 3.81 (s, 3H), 3.80 (s, 3H), 3.59 (d, J = 14.4 Hz, 1H), 3.52 (d, J = 14.4 Hz, 1H), 2.47 (s, 3H), 1.91 (s, 3H), 1.28 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.7, 165.5, 163.7, 159.4, 148.0, 142.4, 131.6, 131.1, 130.4, 129.1, 127.5, 124.2, 122.2, 117.7, 113.9, 113.6, 112.3, 60.7, 55.4, 55.2, 46.8, 24.7, 20.9, 14.1. HRMS (ESI) Calcd for C 28 H 29 7 : [M+H] + 477.1913, found: 477.1921. Ethyl 7-(2-methoxyphenyl)-2-(2-(2-methoxyphenyl)-2-oxoethyl)-2,5-dimethyl C 2 Et benzo[d][1,3]dioxole-4-carboxylate (4k) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.58-7.60 (m, 1H), 7.38-7.42 (m, 1H), 7.30-7.35 (m, 1H), 7.25-7.27 (m, 1H), 6.90-7.00 (m, 3H), 6.85 (d, J = 8.4 Hz, 1H), 6.72 (s, 1H), 4.24-4.32 (m, 2H), 3.80 (d, J = 15.2 Hz, 1H), 3.64 (d, J = 15.2 Hz, 1H), 3.77 (s, 3H) 3.74 (s, 3H), 2.42 (s, 3H), 1.87 (s, 3H), 1.29 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 197.2, 165.7, 158.4, 156.7, 147.7, 143.6, 133.6, 130.8, 130.3, 129.4, 128.6, 124.7, 124.7, 121.9, 120.5, 120.5, 117.8, 112.4, 111.4, 111.2, 60.5, 55.5, 55.3, 51.6, 25.0, 20.7, 14.2. HRMS (ESI) Calcd for C 28 H 29 7 : [M+H] + 477.1913, found: 477.1920. Ethyl 7-(2-chlorophenyl)-2-(2-(2-chlorophenyl)-2-oxoethyl)-2,5-dimethyl Cl Cl C 2 Et benzo[d][1,3]dioxole-4-carboxylate (4l) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.42-7.45 (m, 1H), 7.25-7.35 (m, 6H), 7.16-7.20 (m, 1H), 6.64 (s, 1H), 4.34 (q, J = 6.8 Hz, 2H), 3.68 (d, J = 15.2 Hz, 1H), 3.61 (d, J = 15.2 Hz, 1H), 2.43 (s, 3H), 1.89 (s, 3H), 1.35 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 197.9, 165.4, 147.3, 11
143.2, 139.3, 134. 5, 133.1, 131.7, 131.3, 130.9, 130.8, 130.3, 129.8, 129.3, 129.2, 126.7, 126.7, 124.7, 122.6, 117.8, 113.5, 60.8, 50.9, 25.1, 20.6, 14.2. HRMS (ESI) Calcd for C 26 H 23 Cl 2 5 : [M+H] + 485.0923, found: 485.0931. Ethyl 7-(2-fluorophenyl)-2-(2-(2-fluorophenyl)-2-oxoethyl)-2,5-dimethyl F F C 2 Et benzo[d][1,3]dioxole-4-carboxylate (4m) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.69-7.74 (m, 1H), 7.38-7.47 (m, 2H), 7.29-7.34 (m, 1H), 7.09-7.17 (m, 3H), 6.99-7.04 (m, 1H), 6.76 (s, 1H), 4.27-4.35 (m, 2H), 3.69 (d, J = 15.6 Hz, 1H), 3.66 (d, J = 15.6 Hz, 1H), 2.44 (s, 3H), 1.89 (s, 3H), 1.32 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 193.38, 193.35, 165.4, 162.9, 160.9, 160.3, 158.4, 147.7, 143.4, 131.03, 131.0, 130.54, 130.51, 129.7, 129.65, 126.3, 126.2, 124.42, 124.38, 124.30, 124.27, 124.05, 124.02, 123.2, 123.1, 119.1, 117.7, 116.6, 116.4, 116.1, 115.9, 113.2, 60.7, 51.3, 51.2, 25.1, 20.7, 14.2. HRMS (ESI) Calcd for C 26 H 22 F 2 Na 5 : [M+Na] + 475.1333, found: 475.1330. Ethyl 2,5-dimethyl-2-(2-oxo-4-phenylbutyl)-7-phenethylbenzo[d][1,3] C 2 Et dioxole-4-carboxylate (4n) 1 H NMR (400 MHz, CDCl 3 ) δ: 7.25-7.31 (m, 4H), 7.17-7.22 (m, 6H), 6.53 (s, 1H), 4.32 (q, J = 7.2 Hz, 2H), 3.01 (d, J = 13.6 Hz, 1H), 2.95 (d, J = 13.6 Hz, 1H), 2.83-2.94 (m, 8H), 2.45 (s, 3H), 1.75 (s, 3H), 1.33 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 204.9, 165.6, 146.9, 143.7, 141.2, 140.8, 131.4, 128.5, 128.5, 128.3, 128.3, 126.1, 126.0, 125.5, 124.4, 116.8, 112.1, 60.7, 51.3, 45.7, 35.6, 31.4, 29.4, 24.5, 20.8, 14.3. HRMS (ESI) Calcd for C 30 H 33 5 : [M+H] + 473.2328, found: 473.2331. 3. Procedure for the synthesis of (Z/E)-ethyl 2-(2-(2-(2,4-dinitrophenyl)hydrazono)-2-phenylethyl) -2,5-dimethyl-7-phenylbenzo[d][1,3]dioxole-4-carboxylate (4aa) 12
2 N H 3 C C 2 Et 4a CH 3 + NHNH 2 N 2 N 2 CaCl 2 EtH, reflux, 48 h H 3 C C 2 Et N 2 NH N CH 3 4aa To a flask containing ethyl 2,5-dimethyl-2-(2-oxo-2-phenylethyl)-7-phenylbenzo[d][1,3]dioxole-4- carboxylate (4a, 1.0 mmol) and (2,4-dinitrophenyl)hydrazine (1.0 mmol) in ethanol (5 ml) were added anhydrous CaCl 2 (2.0 mmol). The solution was stirred at reflux for 48 h, and then concentrated under vacuum. The residue was purified by column chromatography on silica gel eluenting with ethyl acetate/hexane (1:5) to give 4aa as a mixture of E/Z isomers with a total yield of 52% (E:Z = 10:3). Single crystal of (E)-4aa was obtained by slow evaporation of its chloroform/petroleum ether solution at room temperature. 4. Typical procedure for the preparation of 5-ethoxy-4-(3-methyl-4-oxo-4-phenylbut-1-en-2-yl) furan-3(2h)-one (5b) To a flask containing 2-methyl-1-phenylbuta-2,3-dien-1-one (1 mmol) and ethyl 4-chloro acetoacetate (2, 1.2 mmol) in CH 3 CN (5 ml) were added anhydrous K 2 C 3 (1.0 mmol). The solution was stirred at room temperature for 1 h. The reaction then was quenched with aqueous NH 4 Cl and extracted with ethyl acetate (5 ml 3). The combined organic phases were dried, filtered and concentrated under vacuum. The residue was purified by column chromatography over silica gel using ethyl acetate/hexane (v/v = 1/10) as eluent to give 5b (52%). 5a, 5c and 5d were obtained in a similar manner. Et 5-Ethoxy-4-(4-oxo-4-phenylbut-1-en-2-yl)furan-3(2H)-one (5a) 1 H NMR (CDCl 3, 400 MHz) δ: 7.93-7.90 (m, 2H), 7.47-7.44 (m, 1H), 7.38-7.34 (m, 2H), 5.87 (s, 1H), 4.89 (s, 1H), 4.41 (s, 2H), 4.28-4.23 (m, 2H), 3.97 (s, 2H), 13
1.09-1.05 (m, 3H). 13 C NMR (CDCl 3, 100 MHz) δ:197.5, 194.0, 180.1, 136.9, 132.8, 130.1, 128.4, 128.0, 114.8, 93.8, 74.3, 66.6, 45.1, 14.3. HRMS(ESI): calcd for C 16 H 17 4 : [M+H] + 273.1127, found 273.1124. Et 5-Ethoxy-4-(3-methyl-4-oxo-4-phenylbut-1-en-2-yl)furan-3(2H)-one (5b) 1 H NMR (CDCl 3, 400 MHz) δ: 8.03-8.01 (m, 2H), 7.51-7.49 (m, 1H), 7.43-7.39 (m, 2H), 5.55 (s, 1H), 4.97 (q, J = 7.2 Hz, 1H), 4.95 (s, 1H), 4.57 (s, 2H), 4.45 (q, J = 7.2 Hz, 2H), 1.38-1.33 (m, 6H). 13 C NMR (CDCl 3, 100 MHz) δ: 201.1, 194.0, 180.7, 136.8, 136.6, 132.4, 128.7, 128.3, 113.1, 94.0, 74.3, 66.7, 43.9, 16.8, 14.6. HRMS(ESI): calcd for C 17 H 19 4 : [M+H] + 287.1283, found 287.1279. 5-Ethoxy-4-(4-oxo-1-phenylpent-1-en-2-yl)furan-3(2H)-one (5c) Et H 3 C 1 H NMR (CDCl 3, 400 MHz) δ: 7.25-7.21 (m, 2H), 7.42 (m, 1H), 7.16-7.11 (m, 2H), 4.48 (s, 2H), 4.44 (q, J = 7.2 Hz, 2H), 3.63 (s, 2H), 2.14 (s, 3H), 1.38 (t, J = 7.2 Hz, 3H). 13 C NMR (CDCl 3, 100 MHz) δ: 206.8, 194.1, 180.2, 137.6, 128.5, 128.1, 126.5, 123.7, 94.6, 74.1, 66.9, 44.5, 29.4, 14.7. HRMS(ESI): calcd for C 17 H 19 4 : [M+H] + 287.1283, found 287.1278. 5-Ethoxy-4-(1-(4-methoxyphenyl)-4-oxopent-1-en-2-yl)furan-3(2H)-one (5d) H 3 C Et H 3 C 1 H NMR (CDCl 3, 400 MHz) δ: 7.37 (s, 1H), 7.09 (d, J = 8.8 Hz, 2H), 6.83 (d, J = 8.8 Hz, 2H), 4.54 (s, 2H), 4.50 (q, J = 7.2 Hz, 2H), 3.78 (s, 3H), 3.68 (s, 2H), 2.19 (s, 3H), 1.45 (t, J = 7.2 Hz, 3H). 13 C NMR (CDCl 3, 100 MHz) δ: 207.1, 180.2, 158.4, 130.1, 129.7, 128.6, 122.5, 113.6, 95.0, 74.1, 66.8, 55.2, 44.6, 29.5, 14.7. HRMS(ESI): calcd for C 18 H 21 5 : [M + H] + 317.1389, found 317.1386. 5. Procedure for the synthesis of ethyl 2,3-dihydroxy-5-methylbiphenyl-4-carboxylate (6a) from 4a 14
To a flask containing ethyl 2,5-dimethyl-2-(2-oxo-2-phenylethyl)-7-phenylbenzo[d][1,3]dioxole-4- carboxylate (4a, 1.0 mmol) in CH 2 Cl 2 (5 ml) was added BBr 3 (5.0 mmol, 1M solution in methylene chloride) at 0 C. The mixture was stirred at 0 C for 2 h. Upon completion, the mixture was quenched with water and extracted with CH 2 Cl 2 (5 ml 3). The combined organic phases were dried, filtered and concentrated under vacuum. The residue was purified by column chromatography on silica gel eluenting with ethyl acetate/hexane (v/v = 1/25) to give 6a (80%). 1 H NMR (400 MHz, CDCl 3 ) δ: 11.93 (s, 1H), 7.66 (d, J = 7.2 Hz, 2H), 7.45 (t, J = 8.0 H 3 C Ph H H C 2 Et Hz, 2H), 7.37 (t, J = 7.2 Hz, 1H), 5.92 (s, 1H), 6.76 (s, 1H), 4.47 (q, J = 7.2 Hz, 2H), 2.54 (s, 3H), 1.46 (t, J = 7.2 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ) δ: 171.9, 150.4, 140.3, 136.9, 130.9, 130.93, 129.0, 128.6, 128.2, 127.8, 126.9, 123.4, 110.6, 61.8, 23.4, 14.2. HRMS (ESI) Calcd for C 16 H 16 Na 4 : [M+Na] + 295.0946, found: 295.0951. 6. Procedure for the preparation of 4a through the reacion of 1a with 6a To a flask containing 1-phenylbuta-2,3-dien-1-one (1a, 0.5 mmol) and ethyl 2,3-dihydroxy-5-methyl biphenyl-4-carboxylate (6a, 0.5 mmol) in toluene (5 ml) were added anhydrous K 2 C 3 (0.75 mmol) and tetrabutyl ammonium bromide (TBAB) (0.03 mmol). The solution was stirred at room temperature for 30 min. The reaction then was quenched with aqueous NH 4 Cl and extracted with ethyl acetate (5 ml 3). The combined organic phases were dried, filtered and concentrated under vacuum. The residue was purified by column chromatography on silica gel eluenting with ethyl acetate/hexane (v/v = 1/10) to give ethyl 2,5-dimethyl-2-(2-oxo-2-phenylethyl)-7-phenylbenzo[d][1,3]dioxole-4-carboxylate (4a, 86%). 15
III. Copies of 1 H and 13 C NMR spectra of 3a-3s, 4a-4n, 5a-5d and 6a 7.715 7.695 7.461 7.455 7.444 7.440 7.433 7.414 7.398 7.263 6.022 4.685 4.370 4.353 4.334 4.317 2.209 1.371 1.354 1.335 3a C 2 Et 3.13 3.01 3.16 2.03 2.02 2.04 1.00 8 6 4 2 0 PPM 187.235 167.673 165.013 149.421 134.286 133.372 131.192 128.723 127.108 106.935 77.466 77.428 77.108 76.788 61.455 24.822 14.145 3a C 2 Et 16
187.159 167.764 165.356 149.718 141.846 133.928 130.575 129.462 127.161 106.211 77.458 77.405 77.085 76.765 61.394 24.837 21.438 14.138 3b C 2 Et 17
18
7.703 7.689 7.681 7.667 7.260 7.101 7.081 7.059 5.939 4.656 4.347 4.330 4.311 4.293 2.185 1.348 1.330 1.312 F 3d C 2 Et 2.99 3.08 2.01 2.08 2.00 2.04 1.00 9 8 7 6 5 4 3 2 1 PPM 187.014 167.558 163.977 163.283 149.261 134.317 129.645 129.615 129.348 129.264 115.958 115.737 106.608 77.458 77.390 77.070 76.750 61.447 24.776 14.107 F 3d C 2 Et 19
7.629 7.608 7.370 7.349 7.260 5.976 4.651 4.348 4.331 4.312 4.294 2.185 1.349 1.332 1.313 Cl 3e C 2 Et 3.02 3.15 2.03 2.03 1.00 2.00 2.04 8 7 6 5 4 3 2 1 0 PPM 20
7.562 7.540 7.533 7.511 7.259 5.990 4.658 4.349 4.332 4.315 4.301 2.191 1.350 1.333 1.321 Br 3f C 2 Et 4.02 2.98 3.00 2.02 1.98 1.00 8 6 4 2 0 PPM 187.113 167.520 163.733 149.025 134.644 132.312 131.947 128.487 125.759 107.126 77.443 77.413 77.093 76.772 61.539 24.814 14.153 Br 3f C 2Et 21
7.813 7.792 7.656 7.637 6.073 4.684 4.358 4.339 4.322 4.304 2.207 1.355 1.338 1.319 F 3 C 3g C 2 Et 3.01 3.06 2.05 2.08 1.00 2.00 2.03 8 6 4 2 0 PPM 187.190 167.292 162.765 148.385 136.862 135.269 132.572 132.244 127.115 125.652 125.614 125.576 108.482 77.458 77.367 77.245 77.047 76.727 61.546 24.677 14.084 F 3C 3g C 2 Et 22
7.483 7.463 7.389 7.382 7.376 7.369 7.356 7.335 7.259 7.145 7.139 7.125 7.118 7.104 7.098 6.001 4.651 4.347 4.328 4.311 4.293 2.182 1.346 1.329 1.311 F 3h C 2 Et 3.00 3.07 1.92 1.07 1.03 1.00 2.00 2.05 10 8 6 4 2 0 PPM 187.212 167.398 164.015 163.161 161.561 148.705 135.742 135.658 134.888 130.331 130.255 122.573 122.543 117.985 117.780 113.939 113.703 107.690 77.443 77.390 77.070 76.757 61.478 24.685 14.099 F 3h C 2Et 23
7.660 7.577 7.558 7.412 7.391 7.353 7.334 7.314 7.259 5.992 4.659 4.355 4.337 4.320 4.301 2.191 1.355 1.338 1.319 Cl 3i C 2Et 3.02 3.14 1.05 0.99 1.08 1.00 1.09 2.00 2.05 10 8 6 4 2 0 PPM 187.174 167.383 163.077 148.667 135.277 134.934 134.820 130.926 129.965 126.955 125.019 107.720 77.474 77.375 77.054 76.742 61.508 24.723 14.115 Cl 3i C 2 Et 24
7.817 7.624 7.605 7.566 7.563 7.546 7.294 7.275 7.259 7.254 5.983 4.661 4.358 4.339 4.321 4.304 2.193 1.357 1.340 1.322 Br 3j C 2Et 3.13 3.13 2.07 2.09 0.97 1.02 1.09 1.02 1.00 8 6 4 2 0 PPM 187.167 162.963 148.659 148.621 135.513 134.949 133.844 130.209 129.859 125.477 122.870 107.736 77.481 77.375 77.054 76.734 61.516 24.738 14.130 Br 3j C 2Et 25
7.497 7.480 7.307 7.287 7.266 7.259 7.241 5.995 4.653 4.354 4.336 4.317 4.300 2.377 2.194 1.356 1.338 1.321 3k C 2 Et 2.00 2.15 1.00 2.00 2.02 2.98 3.00 3.06 8 6 4 2 0 PPM 187.235 167.680 165.249 149.452 138.440 134.180 133.357 132.000 128.601 127.710 124.334 106.882 77.481 77.420 77.100 76.780 61.394 24.784 21.362 14.130 3k C 2Et 26
186.892 167.802 165.257 151.860 149.894 148.880 133.517 125.980 121.049 110.845 109.839 105.518 77.451 77.420 77.100 76.780 61.348 55.991 24.883 14.115 3l C 2 Et 27
7.522 7.517 7.502 7.499 7.403 7.398 7.382 7.364 7.359 7.258 6.990 6.988 6.969 6.950 6.929 6.127 4.642 4.356 4.338 4.321 4.303 3.869 2.155 1.360 1.341 1.323 3m C 2 Et 1.13 1.02 2.13 1.00 2.03 2.16 3.22 3.02 3.17 10 8 6 4 2 0 PPM 188.500 167.825 163.138 158.033 149.436 134.241 132.023 130.316 123.366 120.546 112.323 111.508 77.504 77.397 77.077 76.757 61.340 55.770 24.700 14.138 3m C 2 Et 28
7.623 7.618 7.604 7.599 7.584 7.580 7.392 7.378 7.375 7.373 7.367 7.359 7.259 7.189 7.187 7.171 7.151 7.149 7.121 7.100 7.098 7.092 7.071 6.081 4.646 4.345 4.327 4.309 4.292 2.157 1.345 1.327 1.310 F 3n C 2Et 2.97 3.09 2.02 2.04 1.02 1.03 0.99 1.02 1.00 10 8 6 4 2 0 PPM 187.913 167.452 161.721 159.823 159.785 159.191 148.728 134.896 132.389 132.297 130.011 124.379 124.341 122.185 122.093 116.621 116.400 112.415 112.308 77.519 77.413 77.093 76.772 61.432 24.647 14.099 F 3n C 2Et 29
7.413 7.393 7.359 7.356 7.341 7.321 7.318 7.286 7.268 7.259 7.249 5.679 4.692 4.343 4.325 4.308 4.289 2.139 1.344 1.327 1.308 Cl 3o C 2Et 3.03 3.03 2.00 1.02 1.06 1.00 2.02 2.03 8 7 6 5 4 3 2 1 0 PPM 187.532 167.437 163.862 148.293 134.965 134.126 133.867 131.596 131.428 130.384 126.810 112.011 77.428 77.108 76.788 61.462 24.471 14.115 Cl 3o C 2Et 30
187.296 167.406 164.929 148.339 136.138 134.865 133.532 131.741 127.367 123.076 111.569 77.611 77.466 77.146 76.826 61.432 30.827 24.464 14.107 Br 3p C 2Et 31
8.056 8.035 7.924 7.903 7.879 7.858 7.600 7.583 7.557 7.535 7.513 7.497 7.479 7.459 7.440 7.260 5.806 4.824 4.407 4.389 4.371 4.354 2.209 1.401 1.383 1.366 3q C 2Et 4.14 3.04 3.14 1.03 2.11 1.00 1.99 2.05 9 8 7 6 5 4 3 2 1 0 PPM 186.671 167.650 166.530 149.238 134.439 133.722 132.701 131.329 131.086 128.693 128.571 127.184 126.338 124.989 124.913 111.752 77.466 77.329 77.146 76.826 61.539 24.746 14.191 3q C 2Et 32
7.340 7.323 7.304 7.277 7.259 7.253 7.241 7.227 7.224 7.206 5.289 4.422 4.317 4.299 4.282 4.264 3.557 2.034 1.329 1.311 1.294 3r C 2 Et 3.22 2.12 1.00 2.03 2.14 1.99 2.98 3.22 8 7 6 5 4 3 2 1 0 PPM 186.999 168.968 167.551 148.941 136.214 133.913 128.929 128.723 127.115 108.894 77.405 77.085 76.772 61.310 42.106 24.456 14.084 3r C 2 Et 33
7.290 7.272 7.253 7.202 7.183 7.165 7.151 7.134 5.191 4.407 4.303 4.286 4.267 4.249 2.875 2.857 2.837 2.589 2.570 2.551 1.983 1.318 1.301 1.283 3s C 2 Et 2.19 3.34 1.00 2.01 2.24 2.17 2.01 3.00 3.23 8 6 4 2 0 PPM 186.869 169.525 167.612 149.208 140.162 133.623 128.502 128.334 126.338 108.551 77.527 77.207 76.887 76.833 61.257 37.602 33.349 24.418 14.099 3s C 2 Et 34
195.123 165.387 147.943 142.791 137.220 135.094 133.235 131.642 128.632 128.517 128.472 127.915 127.786 124.433 122.756 117.757 112.941 77.481 77.161 76.841 60.693 46.945 24.791 20.806 14.145 4a C 2 Et 35
7.919 7.914 7.905 7.902 7.897 7.888 7.883 7.593 7.588 7.579 7.571 7.562 7.557 7.259 7.068 7.063 7.051 7.046 7.029 7.024 7.021 7.016 6.999 6.983 6.978 6.814 4.325 4.321 4.306 4.303 4.289 4.286 4.271 4.267 3.633 3.597 3.562 3.527 2.446 1.911 1.308 1.291 1.273 F 4b F C 2Et 2.03 1.96 4.05 1.00 1.98 1.96 2.95 2.97 3.39 8 6 4 2 0PPM 193.522 167.086 165.234 164.548 163.702 161.233 147.836 142.517 133.631 133.600 131.794 131.375 131.284 131.047 131.009 129.653 129.569 123.358 122.512 117.696 115.600 115.547 115.379 115.333 112.979 77.390 77.070 76.750 60.761 46.998 24.829 20.790 14.107 F F 4b C 2Et 200 150 100 50 0PPM 36
7.802 7.797 7.785 7.780 7.528 7.524 7.512 7.507 7.339 7.333 7.321 7.317 7.310 7.307 7.301 7.296 7.284 7.279 6.823 4.328 4.326 4.309 4.292 4.273 3.627 3.592 3.550 3.515 2.450 1.908 1.314 1.297 1.278 Cl 4c Cl C 2Et 2.092.07 4.15 1.00 2.04 2.01 3.04 3.09 3.33 10 8 6 4 2 0 PPM 193.926 165.181 147.844 142.608 139.834 135.414 133.951 133.364 131.886 130.003 129.119 128.708 123.114 122.398 117.719 113.245 77.382 77.062 76.750 60.837 47.036 24.875 20.836 14.153 Cl 4c Cl C 2Et 37
7.701 7.681 7.480 7.475 7.458 7.447 7.439 7.433 7.426 7.417 7.259 6.802 4.308 4.289 4.272 4.254 3.604 3.568 3.527 3.491 2.429 1.885 1.296 1.278 1.261 Br 4d Br C 2Et 6.17 2.12 1.00 2.05 2.03 3.08 3.13 3.47 8 6 4 2 0 PPM 194.102 165.143 147.828 142.570 135.788 133.806 131.886 131.703 131.657 130.072 129.401 128.594 123.099 122.314 122.192 117.696 113.276 77.405 77.085 76.765 60.830 47.006 24.868 20.806 14.153 Br Br 4d C 2 Et 38
7.962 7.941 7.690 7.670 7.608 7.585 7.563 7.259 6.852 4.312 4.294 4.276 4.259 3.699 3.663 3.613 3.577 2.436 1.921 1.296 1.278 1.261 CF 3 CF 3 4e C 2 Et 4.11 2.13 2.28 1.00 2.07 2.02 3.02 3.10 3.31 8 6 4 2 0 PPM 194.140 165.005 142.875 147.767 139.621 138.447 132.000 128.868 128.052 125.477 125.439 125.408 125.370 125.332 122.695 122.672 122.581 117.803 113.847 77.329 77.009 76.696 60.868 47.288 24.951 20.669 14.038 CF 3 CF 3 4e C 2Et 39
7.658 7.639 7.585 7.561 7.402 7.383 7.345 7.326 7.305 7.292 7.286 7.210 7.205 7.189 7.184 7.170 7.168 7.164 7.014 7.009 6.993 6.989 6.972 6.967 6.848 4.331 4.326 4.312 4.308 4.295 4.291 4.277 4.273 3.657 3.621 3.587 3.551 2.450 1.919 1.315 1.298 1.279 F F 4f C 2Et 3.13 1.041.121.15 1.00 1.08 1.02 2.08 1.98 3.09 3.06 3.29 10 8 6 4 2 0 PPM 193.804 165.158 164.030 163.923 161.591 161.454 147.866 142.745 139.202 139.141 137.129 137.053 131.848 130.171 130.095 130.011 129.927 124.417 124.387 123.480 123.450 122.969 122.489 120.378 120.165 117.764 115.250 115.021 114.876 114.861 114.655 113.421 77.405 77.085 76.765 60.822 47.097 24.890 20.752 14.115 F F 4f C 2 Et 40
7.834 7.830 7.826 7.731 7.728 7.725 7.712 7.709 7.705 7.573 7.570 7.568 7.492 7.487 7.485 7.481 7.476 7.470 7.465 7.452 7.450 7.447 7.445 7.433 7.430 7.427 7.424 7.301 7.281 7.272 7.266 7.259 7.239 6.828 6.827 4.331 4.322 4.312 4.305 4.295 4.287 4.277 4.270 3.645 3.609 3.567 3.531 2.451 1.917 1.312 1.295 1.276 Cl Cl 4g C 2 Et 3.17 2.12 1.02 1.02 1.04 1.00 2.04 2.02 3.01 3.06 3.27 12 10 8 6 4 2 0 PPM 193.820 165.120 138.630 147.882 142.730 136.733 134.873 134.423 133.143 131.962 129.775 129.737 128.456 127.938 127.786 126.666 126.056 122.832 122.520 117.764 113.436 77.420 77.100 76.780 60.837 47.029 24.936 20.813 14.153 Cl Cl 4g C 2Et 41
7.991 7.987 7.982 7.783 7.780 7.776 7.763 7.760 7.759 7.757 7.726 7.722 7.718 7.620 7.617 7.615 7.612 7.600 7.597 7.595 7.539 7.537 7.535 7.520 7.517 7.515 7.513 7.445 7.442 7.440 7.437 7.425 7.422 7.420 7.248 7.228 7.208 7.189 6.830 6.828 4.329 4.320 4.311 4.301 4.293 4.284 3.646 3.610 3.562 3.527 2.458 1.923 1.317 1.299 1.282 Br Br 4h C 2Et 2.10 1.062.25 1.03 1.07 1.00 1.18 2.09 2.01 2.97 3.05 3.88 12 10 8 6 4 2 0 PPM 193.759 165.127 138.828 147.866 142.715 137.007 136.085 131.985 131.406 130.872 130.644 130.011 127.100 126.559 122.924 122.756 122.657 122.535 117.749 113.459 77.359 77.047 76.727 60.860 47.006 24.944 20.829 14.160 Br Br 4h C 2Et 42
7.734 7.732 7.718 7.445 7.443 7.428 7.345 7.326 7.287 7.267 7.259 7.247 7.144 7.126 6.899 6.897 4.351 4.342 4.333 4.331 4.324 4.312 4.307 4.295 4.288 4.285 4.277 3.691 3.655 3.619 3.583 2.498 2.378 2.354 2.329 1.946 1.320 1.301 1.284 4i C 2Et 2.14 2.07 2.16 1.041.00 1.22 2.07 2.06 2.89 3.11 3.05 3.33 2.91 8 6 4 2 0 PPM 195.389 165.463 138.325 138.066 147.996 142.806 137.304 135.025 134.027 131.573 129.104 128.723 128.502 128.403 125.926 125.126 124.593 122.809 117.772 112.765 77.420 77.100 76.780 60.708 46.952 24.807 21.499 21.202 20.874 14.145 4i C 2Et 43
7.888 7.881 7.859 7.852 7.590 7.583 7.578 7.561 7.553 7.259 6.911 6.903 6.881 6.874 6.854 6.818 6.810 6.788 6.782 4.319 4.312 4.301 4.294 4.283 4.277 4.266 4.260 3.813 3.809 3.617 3.582 3.533 3.497 2.469 1.911 1.299 1.280 1.263 4j C 2Et 6.10 2.02 2.011.99 1.97 2.04 0.99 2.04 3.00 2.98 3.90 10 8 6 4 2 0 PPM 193.720 165.493 163.649 159.389 148.011 142.402 131.634 131.086 130.362 129.142 127.473 124.189 122.238 117.704 113.916 113.558 112.262 77.382 77.070 76.750 60.655 55.381 55.221 46.800 24.669 20.920 14.138 4j C 2Et 44
7.605 7.601 7.586 7.582 7.425 7.421 7.407 7.404 7.402 7.399 7.386 7.381 7.348 7.343 7.329 7.327 7.325 7.323 7.308 7.305 7.270 7.267 7.260 7.252 7.247 7.002 6.999 6.982 6.980 6.964 6.945 6.944 6.939 6.922 6.921 6.903 6.901 6.863 6.843 6.720 6.718 4.310 4.301 4.298 4.292 4.281 4.274 4.262 4.256 4.245 3.821 3.783 3.772 3.736 3.655 3.617 2.428 1.871 1.310 1.292 1.274 4k C 2 Et 0.00 1.04 3.44 4.39 1.00 2.04 2.87 2.92 1.34 1.04 3.05 3.02 3.64 12 10 8 6 4 2 0PPM 197.226 165.707 158.421 156.691 147.737 143.568 133.547 130.811 130.293 129.348 128.632 124.730 124.707 121.941 120.531 120.462 117.795 112.430 111.363 111.241 77.329 77.009 76.689 60.540 55.472 55.259 51.548 25.020 20.699 14.160 4k C 2Et 45
7.447 7.437 7.430 7.424 7.345 7.327 7.305 7.296 7.289 7.280 7.273 7.270 7.263 7.256 7.212 7.197 7.188 7.184 7.177 7.170 7.164 7.156 6.641 4.363 4.345 4.328 4.309 3.707 3.669 3.620 3.583 2.428 1.889 1.369 1.352 1.334 Cl Cl 4l C 2 Et 7.16 1.171.06 1.00 2.16 2.08 3.08 3.10 3.18 10 8 6 4 2 0PPM 197.950 165.348 134.477 147.272 143.241 139.331 133.067 131.733 131.299 130.895 130.773 130.247 129.798 129.279 129.173 126.696 126.681 124.730 122.581 117.772 113.459 77.375 77.054 76.742 60.815 50.892 25.066 20.600 14.244 Cl Cl 4l C 2 Et 46
7.735 7.731 7.716 7.712 7.697 7.693 7.470 7.466 7.458 7.452 7.450 7.448 7.440 7.433 7.427 7.419 7.403 7.399 7.384 7.380 7.340 7.335 7.327 7.319 7.317 7.306 7.302 7.296 7.287 7.283 7.260 7.169 7.151 7.131 7.116 7.113 7.109 7.105 7.083 7.034 7.032 7.012 7.005 6.985 6.983 6.758 4.337 4.331 4.319 4.313 4.301 4.295 4.284 4.277 3.719 3.716 3.678 3.667 3.664 3.628 3.624 2.435 1.889 1.337 1.320 1.302 F F 4m C 2 Et 3.30 2.24 1.06 1.08 1.11 1.03 2.12 2.07 3.10 3.12 3.31 12 10 8 6 4 2 0 PPM 193.378 193.347 165.379 162.933 160.898 160.334 158.406 134.614 147.722 134.523 143.401 131.032 131.002 130.537 130.514 129.721 129.645 126.277 126.155 124.417 124.379 124.295 124.265 124.052 124.021 123.236 123.091 119.121 117.696 116.583 116.347 116.073 115.852 113.223 77.336 77.016 76.696 60.716 51.304 51.228 25.081 20.661 14.145 F F 4m C 2 Et 47
7.305 7.303 7.286 7.268 7.259 7.249 7.224 7.208 7.189 7.172 6.532 4.345 4.328 4.310 4.293 3.027 2.993 2.963 2.942 2.936 2.928 2.920 2.900 2.876 2.867 2.853 2.848 2.841 2.832 2.825 2.446 1.747 1.348 1.329 1.311 4n C 2Et 6.22 4.32 0.99 2.14 4.42 2.38 2.99 2.99 3.61 2.28 1.79 10 8 6 4 2 0 PPM 204.915 165.562 146.990 143.652 141.221 140.832 131.383 128.479 128.456 128.327 128.304 126.094 126.041 125.492 124.433 116.842 112.064 77.458 77.138 76.826 60.655 51.327 45.756 35.598 31.383 29.417 24.509 20.798 14.305 4n C 2Et 48
8.985 8.977 8.909 8.903 8.196 8.190 8.182 8.173 8.167 8.158 11.734 8.152 11.266 7.919 7.894 7.789 7.766 7.662 7.645 7.641 7.469 7.463 7.455 7.450 7.445 7.430 7.423 7.414 7.364 7.347 7.343 7.335 7.321 7.318 7.307 7.303 7.296 7.260 7.238 7.219 7.203 7.195 7.109 7.089 7.071 6.814 6.647 4.321 4.304 4.286 4.268 4.151 4.146 4.133 4.128 4.111 3.578 3.540 3.517 3.481 3.442 3.407 2.436 2.315 2.081 1.840 1.343 1.324 1.307 1.301 1.283 1.264 1.258 1.240 2 N NH N N 2 4aa H 3 C C 2 Et CH 3 0.68 1.00 0.98 0.68 1.71 1.09 0.72 1.43 5.08 3.70 5.30 2.17 1.04 0.71 3.43 2.09 1.60 2.97 3.05 2.11 2.08 8.30 14 12 10 8 6 4 2 0-2 PPM As a mixture a E/Z isomers (E/Z = 10/7) 49
7.931 7.919 7.899 7.472 7.453 7.437 7.435 7.380 7.362 7.342 5.869 4.889 4.410 4.279 4.262 4.246 4.244 4.228 3.973 1.087 1.085 1.069 1.066 1.052 1.049 Et 5a 2.29 1.06 2.60 0.96 0.96 1.87 2.04 2.00 3.06 8 7 6 5 4 3 2 1 PPM 197.508 193.957 180.125 136.893 132.762 130.064 128.441 128.014 114.747 93.843 77.573 77.253 76.933 74.280 66.568 45.063 14.259 Et 5a 50
8.031 8.013 8.009 7.513 7.495 7.477 7.431 7.412 7.393 7.260 5.547 4.996 4.978 4.961 4.952 4.568 4.565 4.480 4.462 4.444 4.426 1.377 1.359 1.350 1.340 1.333 Et 5b 6.26 1.99 1.08 2.19 1.00 2.00 1.93 2.07 8 7 6 5 4 3 2 1 0 PPM 201.067 193.995 180.697 136.793 136.603 132.412 128.708 128.334 113.123 93.980 77.382 77.062 76.742 74.296 66.713 43.851 16.759 14.557 Et 5b 51
7.424 7.250 7.232 7.214 7.156 7.125 7.106 4.479 4.465 4.447 4.430 4.411 3.629 2.139 1.396 1.379 1.361 Et 5c 1.02 2.08 3.01 2.02 1.98 2.00 3.00 3.06 7 6 5 4 3 2 1 0 PPM 206.836 194.117 180.239 137.594 128.479 128.121 126.536 123.693 94.636 77.557 77.237 76.917 74.136 66.850 44.483 29.440 14.656 Et 5c 52
7.365 7.259 7.106 7.084 6.839 6.817 4.537 4.529 4.510 4.493 4.475 3.782 3.677 2.194 1.464 1.447 1.428 Et 5d 0.97 1.93 2.02 1.84 2.18 3.02 2.00 3.04 3.00 8 7 6 5 4 3 2 1 0 PPM 53
11.930 7.670 7.652 7.507 7.480 7.470 7.452 7.432 7.385 7.366 7.348 7.260 6.762 5.918 4.498 4.481 4.463 4.445 2.540 1.476 1.459 1.441 H 3 C C 2 Et H H 6a 2.89 2.91 3.20 2.12 2.11 1.00 1.09 1.04 1.01 12 10 8 6 4 2 0 PPM 171.971 150.442 140.284 136.885 130.964 130.933 129.043 128.586 128.243 127.748 126.986 123.381 110.601 77.336 77.024 76.704 61.821 23.366 14.168 H 6a H 3 C H CEt 54
IV. X-ray crystallography The crystallographic data (excluding structure factors) for 3f, (E)-4aa (hydrazone of 4a) and 5c have been deposited at the Cambridge Crystallographic Data Centre. CCDC 892529, 913070 and 909448 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. 1. X-ray crystal structure of ethyl 7-(4-bromophenyl)-5-methyl-3-oxo-2,3-dihydrooxepine- 4- carboxylate (3f) Fiure 1 The RTEP drawing of 3f 55
2. X-ray crystal structure of (E)-ethyl 2-(2-(2-(2,4-dinitrophenyl)hydrazono)-2-phenylethyl)-2,5- dimethyl-7-phenylbenzo[d][1,3]dioxole-4-carboxylate (E-4aa) Fiure 2 The RTEP drawing of (E)-4aa 56
3. X-ray crystal structure of 5-Ethoxy-4-(4-oxo-1-phenylpent-1-en-2-yl)furan-3(2H)-one (5c) Fiure 3 The RTEP drawing of 5c 57
V. References (1) A. Sniady, M. S. Morreale, R. Dembinski, rg. Synth., 2007, 84, 199-208. (2) W. Wu, Z. Yao, Y. Li, J. Li, Y. Xia, Y. Wu, J. rg. Chem., 1995, 60, 3257-3259. (3) N. A. Petasis, K. A. Teets, J. Am. Chem. Soc., 1992, 114, 10328-10334. 58