β-borylallylsilanes as a New Tool for Convenient Synthesis of Alkenylboranes

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1 Supporting Information β-borylallylsilanes as a New Tool for Convenient Synthesis of Alkenylboranes Michinori Suginome,* Yutaka Ohmori, and Yoshihiko Ito * Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto , Japan CONTENTS p1 9: Experimental procedures and characterization data for the new compounds p10 13: Details of a single-crystal X-ray analysis of 7. 1

2 Experimental Procedures General. All reactions were performed under a nitrogen atmosphere with magnetic stirring. Column chromatography was performed with Cosmosil 140C 18 -OPN (silica gel endcapped with ODS, Nacalai) or Wakogel C-200 (silica gel, µm, Wako). 1 H and 13 C NMR spectra were recorded on a Varian Gemini 2000 ( 1 H at MHz and 13 C at MHz) spectrometer using the solvent as internal standard. High resolution mass spectra were recorded on a JEOL JMS-HX110A (FAB) or a JEOL JMS-SX102A (EI) spectrometer. Infrared spectra were recorded on a Hitachi spectrometer. Anhydrous THF and CH 2 Cl 2 were purchased from Kanto Chemical Co., Inc. Benzene (LiAlH 4 ), octane (CaH 2 ) and diglyme (LiAlH 4 ) were distilled from the indicated drying agents under nitrogen. Pd(acac) 2 (Mitsuwa), TiCl 4 (Kishida), AlCl 3 (Wako), (E)-bromopropene (Aldrich), p-iodonitrobenzene (Tokyo Kasei), trimethylamine oxide dihydrate (Tokyo Kasei), sodium ethoxide (Wako), Rh(CO) 2 (acac) (Aldrich), acetic anhydride (Wako), pinacol (Tokyo Kasei), and 1,4- bis(diphenylphosphino)butane (dppb, Kanto) were used as received from the commercial sources. TMSOTf (Nacalai), 2a (Aldrich), 2d (Nacalai), propionaldehyde (Wako), heptanal (Wako), cyclohexanecarboxaldehyde (Tokyo Kasei), pivalaldehyde (Aldrich), benzaldehyde (Nacalai), benzyloxyacetaldehyde (Aldrich), triethylamine (Wako), triethylphosphite (Nacalai), and methyl vinyl ketone (Wako) were obtained from the commercial sources and purified by distillation. Acetals 2b and 2c were prepared by reactions of methanol with cyclohexanecarboxaldehyde and dihydropyran, respectively, in the presence of an acid catalyst. Tetrakis(triphenylphosphine)- palladium, i dimethylphenylsilylpinacol borane, ii β-borylallylsilanes 1a-c, iii and allenes 8 and 9 iv were prepared according to the literature method. General Procedure for the reaction of β-borylallylsilanes 1 with acetals (eq 2, Table 1). To a solution of 1 (0.12 mmol) and acetal (0.15 mmol) in CH 2 Cl 2 (0.12 ml) was added Lewis acid (0.15 mmol; TiCl 4 : 2.0 M in CH 2 Cl 2, 74 µl; AlCl 3 : 19.7 mg) at 78 C. The mixture was stirred for 3 h at the temperature indicated in Table 1. To the mixture was added saturated NaHCO 3 aq. at the (i) Coulson, D. R. Inorg. Synth. 1972, 13, 121. (ii) Suginome, M.; Matsuda, T.; Ito, Y. Organometallics 2000, 19, (iii) Suginome, M.; Ohmori, Y.; Ito, Y. J. Organomet. Chem. 2000, 611, 403. (iv) Price, W. A.; Patten, T. E. J. Chem. Ed. 1991, 68,

3 temperature ( 78 or 20 C), and the mixture was warmed to room temperature. The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. The residue was subjected to column chromatography on ODS-endcapped silica gel (hexane:etoac = 300/1 ~ 50/1) to give homoallyl ethers 3. (E)-6-Ethoxy-1-phenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-octene (3aa). 1 H NMR (CDCl 3 ) δ 0.88 (t, J = 7.2 Hz, 3H), 1.15 (t, J = 6.9 Hz, 3H), 1.25 (s, 12H), 1.33 (sextet, J = 7.2 Hz, 1H), (m, 1H), 2.13 (dd, J = 6.9, 12.9 Hz, 1H), 2.37 (dd, J = 5.7, 12.9 Hz, 1H), (m, 4H), (m, 1H), 3.43 (dq, J = 6.9, 9.3 Hz, 1H), 3.53 (dq, J = 6.9, 9.3 Hz, 1H), 6.10 (m, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 9.8, 15.5, 24.7, 24.9, 26.5, 33.0, 36.4, 41.5, 64.3, 80.8, 82.9, 125.6, 128.2, 128.5, 142.3, 147.6; IR (neat) 2984, 1636, 1410, 1146 cm -1. HRMS calcd. for C 22 H 35 BO 3 (M + ): Found: (E)-1-Cyclohexyl-1-methoxy-6-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-hexene (3ab). 1 H NMR (CDCl 3 ) δ (m, 5H), 1.26 (s, 12H), (m, 6H), (m, 2H), (m, 4H), (m, 1H), 3.29 (s, 3H), 6.08 (t, J = 6.9 Hz, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 24.7, 24.9, 26.36, 26.39, 26.6, 27.7, 29.2, 33.1, 36.4, 38.3, 40.8, 58.2, 82.9, 86.3, 125.6, 128.2, 128.5, 142.4, 146.4; IR (neat) 2936, 1636, 1410, 1146 cm -1. Anal. calcd. for C 25 H 39 BO 3 : C, 75.37; H, Found: C, 75.45; (E)-2-[5-Phenyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)penten-1-yl]tetrahydrofuran (3ac). 1 H NMR (CDCl 3 ) δ (m, 1H), 1.25 (s, 12H), (m, 4H), (m, 1H), 2.16 (dd, J = 6.6, 13.2 Hz, 1H), 2.35 (dd, J = 6.6, 13.2 Hz, 1H), (m, 4H), 3.27 (ddt, J = 2.1, 6.6, 10.8 Hz, 1H), 3.37 (dt, J = 2.7, 11.4 Hz, 1H), 3.94 (m, 1H), 6.07 (m, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 23.5, 24.7, 26.1, 31.2, 33.0, 36.4, 43.9, 68.4, 78.0, 82.9, 125.6, 128.2, 128.6, 142.4, 146.8; IR (neat) 2944, 1636, 1410, 1148 cm -1. Anal. calcd. for C 22 H 33 BO 3 : C, 74.16; H, Found: C, 74.11; (E)-6-Methoxy-1,6-diphenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-hexene (3ad). 1 H NMR (CDCl 3 ) δ 1.26 (s, 12H), 2.38 (dd, J = 5.7, 12.9 Hz, 1H), (m, 5H), 3.18 (s, 3H), 4.18 (dd, J = 5.7, 7.5 Hz, 1H), (m, 1H), (m, 10H); 13 C NMR (CDCl 3 ) δ 24.7, 24.9, 33.0, 36.3, 45.6, 56.6, 82.9, 84.5, 125.6, 127.0, 127.2, 128.1, 128.2, 128.5, 142.4, 147.6; IR (neat) 2988, 1636, 1410, 1146 cm -1. Anal. calcd. for C 25 H 33 BO 3 : C, 76.53; H, Found: C, 76.83; H, Ethoxy-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-hexene (3ba). 1 H NMR (CDCl 3 ) δ 0.89 (t, J = 7.2 Hz, 3H), 1.16 (t, J = 6.9 Hz, 3H), 1.26 (s, 12H), 1.39 (sextet, J = 7.2 Hz, 1H), (m, 3

4 1H), 2.23 (dd, J = 6.6, 13.2 Hz, 1H), 2.41 (dd, J = 6.6, 13.2 Hz, 1H), 3.30 (dq, J = 4.8, 6.6 Hz, 1H), 3.47 (dq, J = 6.9, 9.3 Hz, 1H), 3.52 (dq, J = 6.9, 9.3 Hz, 1H), 5.64 (d, J = 3.3 Hz, 1H), 5.82 (d, J = 3.3 Hz, 1H); 13 C NMR (CDCl 3 ) δ 9.7, 15.5, 24.6, 24.7, 26.6, 44.2, 64.3, 80.2, 83.3, 131.3; IR (neat) 2988, 1620, 1374, 1146 cm -1. Anal calcd for C 14 H 27 BO 3 : C, 66.16; H, Found: C, 66.24; H, (E)-1-Cyclohexyl-4-ethoxy-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-hexene (3ca). NMR (CDCl 3 ) δ 0.88 (t, J = 7.2 Hz, 3H), (m, 6H), 1.15 (t, J = 6.9 Hz, 3H), 1.26 (s, 12H), (m, 1H), (m, 5H), 2.10 (dd, J = 6.6, 13.2 Hz, 1H), 2.32 (dd, J = 6.6, 13.2 Hz, 1H), (m, 1H), 3.14 (dq, J = 4.2, 6.6 Hz, 1H), 3.43 (dq, J = 6.9, 9.3 Hz, 1H), 3.55 (dq, J = 6.9, 9.3 Hz, 1H), 5.84 (d, J = 9.0 Hz, 1H); 13 C NMR (CDCl 3 ) δ 9.9, 15.5, 24.6, 24.8, 25.8, 25.9, 26.0, 26.6, 33.6, 39.6, 41.7, 64.4, 80.9, 82.8, 154.1; IR (neat) 2936, 1634, 1146, 866 cm -1. Anal. calcd. for C 20 H 37 BO 3 : C, 71.42; H, Found: C, 71.56; H Synthesis of (E)-6-Chloro-1,6-diphenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-hexene (4ad) (eq 3). By the procedure same as that for the synthesis of 3, the title compound was prepared. 1 H NMR (CDCl 3 ) δ 1.24 (s, 12H), (m, 4H), (m, 2H), 5.03 (t, J = 7.5 Hz, 1H), 6.09 (t, J = 7.2 Hz, 1H), (m, 10H); 13 C NMR (CDCl 3 ) δ 24.8, 32.8, 36.2, 47.3, 64.0, 83.0, 125.7, 127.4, 128.0, 128.2, 128.4, 128.6, 142.0, 142.2, 150.9; IR (neat) 2988, 1636, 1412, 1144 cm -1. Anal. calcd. for C 24 H 30 BClO 2 : C, 72.65; H, Found: C, 72.80; H, Synthesis of 8-Phenyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-octen-3-yl acetate (6) (eq 4). To a solution of 1a (48 mg, 0.12 mmol) and propionaldehyde (8.6 mg, 0.15 mmol) in CH 2 Cl 2 (0.12 ml) was added TiCl 4 (2.0 M in CH 2 Cl 2, 74 µl, 0.15 mmol) at 78 C. The mixture was stirred at 78 C for 3 h. To the mixture was added saturated NaHCO 3 aq. at 78 C, and the mixture was warmed to room temperature. The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. To the residue was added pinacol (29 mg, 0.25 mmol), THF (0.5 ml), Et 3 N (37 mg, 51 µl, 0.37 mmol), Ac 2 O (63 mg, 0.62 mmol), and 4-(dimethylamino)pyridine (5 mg) at room temperature. The mixture was stirred for 9 h at room temperature. Addition of water to the mixture followed by extractive workup with EtOAc gave crude material. The residue was subjected to column chromatography on ODS-endcapped silica gel (hexane:etoac = 300/1 ~ 30/1) to give 6 (30 mg, 69%). 1 H NMR (CDCl 3 ) δ 0.86 (t, J = 7.5 Hz, 3H), 1.26 (s, 12H), (m, 2H), 1.97 (s, 3H), 2.20 (dd, J = 7.8, 13.2 Hz, 1H), 2.38 (dd, J = 5.1, 13.2 Hz, 1H), 2.65 (d, J = 3.9 Hz, 4H), 4

5 4.88 (tt, J = 5.1, 7.8 Hz, 1H), 6.11 (m, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 9.6, 21.2, 24.7, 24.8, 26.7, 32.9, 36.3, 41.1, 75.3, 83.0, 125.7, 128.2, 128.5, 142.3, 148.7, 170.8; IR (neat) 2984, 1740, 1246, 1146 cm -1. Anal. calcd. for C 22 H 33 BO 4 : C, 70.97; H, Found: C, 70.69; H, Synthesis of (2R *,4S *,4aR *,10bS * )-2,4-Diethyl-1,4,4a,5,6,10b-hexahydro-10b-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)-2H-naphtho[2,1-c]pyran (7). To a solution of 1a (48 mg, 0.12 mmol) and aldehyde (21 mg, 0.37 mmol) in CH 2 Cl 2 (0.12 ml) was added TMSOTf (82 mg, 0.37 mmol) at 78 C. The mixture was stirred at 0 C for 3 h. To the mixture was added saturated NaHCO 3 aq. at 0 C, and the mixture was warmed to room temperature. The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. The residue was subjected to column chromatography on ODS-endcapped silica gel (hexane:etoac = 300/1) to give 7 (41 mg, 92%). 1 H NMR (CDCl 3 ) δ 0.99 (t, J = 7.5 Hz, 3H), 1.00 (t, J = 7.5 Hz, 3H), 1.09 (s, 12H), (m, 3H), (m, 2H), (m, 2H), 2.10 (tt, J = 8.7, 12.3 Hz, 1H), 2.59 (dd, J = 2.1, 12.3 Hz, 1H), (m, 2H), 3.30 (ddd, J = 2.7, 8.4, 9.6 Hz, 1H), (m, 1H), (m, 3H), 7.26 (d, J = 7.5 Hz, 1H); 13 C NMR (CDCl 3 ) δ 9.6, 10.2, 21.1, 24.3, 24.4, 25.8, 28.6, 29.6, 33.8 (br), 41.1, 45.9, 77.6, 80.7, 82.9, 124.9, 125.3, 125.7, 128.7, 136.8, 142.1; IR (KBr) 2984, 1314, 1142, 856 cm -1. HRMS calcd. for C 23 H 35 BO 3 (M + ): Found: Synthesis of 3-(Dimethylphenylsilyl)-4-(dimethylphenylsilyloxy)-2-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)-1-butene (10) (Scheme 1). To a solution of (η 5 -cyclopentadienyl)(πallyl)palladium (48 mg, 0.23 mmol) and P(OEt) 3 (75 mg, 0.45 mmol) in octane (6.0 ml) were added (dimethylphenylsilyl)pinacolborane (3.4 g, 13 mmol) and 4-(dimethylphenylsilyloxy)-1,2-butadiene (8) (2.3 g, 11 mmol). The mixture was stirrred at 120 C for 2 h. After the mixture was cooled to room temperature, the solvent was evaporated. The residue was subjected to silica gel column chromatography (hexane:acoet:meoh = 100/1/1) to give 10 (3.9 g, 74%). 1 H NMR (CDCl 3 ) δ 0.26 (s, 3H), 0.28 (s, 3H), 1.19 (s, 6H), 1.20 (s, 6H), 2.42 (dd, J = 6.0, 8.1 Hz, 1H), 3.80 (dd, J = 6.0, 9.9 Hz, 1H), 3.88 (dd, J = 8.1, 9.9 Hz, 1H), 5.44 (d, J = 3.0 Hz, 1H), 5.10 (d, J = 3.0 Hz, 1H), (m, 6H), (m, 4H); 13 C NMR (CDCl 3 ) δ 4.3, 3.3, 1.9, 1.8, 24.65, 24.73, 37.3, 64.0, 83.3, 127.5, 127.7, 127.9, 128.7, 129.3, 133.6, 134.3, 138.3, 138.5; IR (neat) 2988, 1604, 1432, 1254 cm -1. Anal calcd. for C 26 H 39 BO 3 Si 2 : C, 66.93; H, Found: C, 66.77; H, (Dimethylphenylsilyl)-5-(dimethylphenylsilyloxy)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)-1-pentene (11). By a procedure similar to that for the synthesis of 10, the title compound 11 was prepared. 1 H NMR (CDCl 3 ) δ 0.22 (s, 3H), 0.25 (s, 3H), 0.30 (s, 6H), 1.17 (s, 12H), (m, 5

6 1H), (m, 1H), 2.11 (dd, J = 3.0, 12.0 Hz, 1H), 3.39 (ddd, J = 6.9, 8.1, 9.6 Hz, 1H), 5.33 (d, J = 2.7 Hz, 1H), 5.77 (d, J = 2.7 Hz, 1H), (m, 6H), (m, 4H); 13 C NMR (CDCl 3 ) δ 5.4, 3.9, 1.9, 1.8, 24.67, 24.71, 29.6, 31.5, 62.6, 83.3, 126.9, 127.5, 127.8, 128.8, 129.5, 133.5, 134.3, 138.3, 138.4; IR (neat) 2988, 1615, 1144, 832 cm -1. Anal. calcd. for C 27 H 41 BO 3 Si 2 : C, 67.48; H, Found: C, 67.32; General procedure for the synthesis of 12 by reaction of 10 with aldehyde (six-membered ring formation; Table 2, entries 1 4). To a solution of 10 (80 mg, 0.17 mmol) and aldehyde (0.17 mmol) in CH 2 Cl 2 (4.0 ml) was added TMSOTf (19 mg, mmol) at 78 C. The mixture was stirred at 78 C for 1 h. To the mixture was added saturated NaHCO 3 aq. at 78 C, and the mixture was warmed to room temperature. The organic materials were extracted with EtOAc, and the extract was dried over MgSO 4, filtered, and evaporated. The residue was subjected to column chromatography on ODS-endcapped silica gel (hexane ~ hexane:etoac = 29/1) to give six-membered cyclic ether Hexyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyran (12a). 1 H NMR (CDCl 3 ) δ 0.86 (t, J = 6.6 Hz, 3H), (m, 10H), 1.25 (s, 12H), (m, 2H), (m, 1H), (m, 2H), (m, 1H); 13 C NMR (CDCl 3 ) δ 14.0, 22.5, 24.65, 24.73, 25.3, 29.3, 31.8, 35.9, 66.7, 73.6, 83.3, 141.0; IR (neat) 2940, 1646, 1322, 1148 cm -1. HRMS calcd. for C 17 H 31 BO 3 (M + ): Found: Cyclohexyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyran (12b). NMR (CDCl 3 ) δ (m, 6H), 1.25 (s, 12H), (m, 4H), (m, 1H), (m, 2H), 3.13 (dt, J = 6.3, 7.2 Hz, 1H), (m, 2H), (m, 1H); 13 C NMR (CDCl 3 ) δ 24.6, 24.7, 26.0, 26.1, 26.6, 28.3, 28.7, 29.0, 42.8, 67.1, 78.0, 83.3, 141.1; IR (neat) 2936, 1648, 1320, 1148 cm -1. HRMS calcd. for C 17 H 29 BO 3 (M + ): Found: t-Butyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyran (12c). 1 H NMR (CDCl 3 ) δ 0.91 (s, 9H), 1.26 (s, 12H), (m, 2H), 3.04 (dd, J = 3.9, 10.2 Hz, 1H), (m, 2H), (m, 1H); 13 C NMR (CDCl 3 ) δ 24.68, 24.71, 25.7, 26.1, 33.8, 67.7, 81.6, 83.3, 141.3; IR (KBr) 2984, 1648, 1360, 1148 cm -1. HRMS calcd. for C 15 H 27 BO 3 (M + ): Found: Phenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyran (12d). 1 H NMR (CDCl 3 ) δ 1.26 (s, 6H), 1.27 (s, 6H), (m, 2H), 4.43 (d, J = 2.7 Hz, 1H), 4.45 (d. J = 2.7 Hz, 1H), 4.48 (dd, J = 4.8, 12.0 Hz, 1H), 6.61 (m, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 24.7, 24.8, 1 H 6

7 33.7, 67.4, 75.6, 83.4, 125.9, 127.4, 128.3, 140.7, 142.7; IR (neat) 2988, 1646, 1356, 1146 cm -1. HRMS calcd. for C 17 H 23 BO 3 (M + ): Found: General procedure for the synthesis of 13 by reaction of 11 with aldehyde (seven-membered ring formation; Table 2, entries 5 9). To a solution of 11 (81 mg, 0.17 mmol) and aldehyde (0.18 mmol) in CH 2 Cl 2 (4.0 ml) was added TMSOTf (41 mg, 0.18 mmol) at 78 C. The mixture was stirred at 78 C for 1 h. To the mixture was added saturated NaHCO 3 aq. at 78 C, and the mixture was warmed to room temperature. The organic materials were extracted with EtOAc, and the extract was dried over MgSO 4, filtered, and evaporated. The residue was subjected to silica gel column chromatography (hexane:meoh = 100/1 ~ hexane:etoac:meoh = 20/1/1) to give seven-membered cyclic ether Hexyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3,6,7-tetrahydrooxepine (13a). NMR (CDCl 3 ) δ 0.87 (t, J = 6.9 Hz, 3H), (m, 10H), 1.25 (s, 12H), (m, 2H), (m, 2H), (m, 1H), 3.39 (ddd, J = 1.8, 7.2, 9.3 Hz, 1H), 3.98 (dt, J = 3.9, 12.3 Hz, 1H), (m, 1H); 13 C NMR (CDCl 3 ) δ 14.0, 22.6, 24.7, 25.8, 29.3, 31.8, 34.1, 36.9, 38.1, 68.5, 80.3, 83.4, 146.4; IR (neat) 2940, 1650, 1330, 1148 cm -1. HRMS calcd. for C 18 H 33 BO 3 (M + ): Found: Cyclohexyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3,6,7-tetrahydrooxepine (13b). 1 H NMR (CDCl 3 ) δ (m, 6H), 1.24 (s, 12H), (m, 5H), (m, 2H), (m, 2H), 3.09 (ddd, J = 1.5, 5.1, 9.0 Hz, 1H), 3.38 (ddd, J = 1.8, 9.9, 12.0 Hz, 1H), 3.95 (dt, J = 5.1, 12.0 Hz, 1H), 6.74 (ddd, J = 2.4, 5.2, 6.9 Hz, 1H); 13 C NMR (CDCl 3 ) δ 24.7, 26.3, 26.4, 26.5, 28.0, 29.5, 33.9, 34.8, 43.5, 68.2, 83.4, 84.4, IR (KBr) 2936, 1638, 1146, 860. HRMS calcd. for C 18 H 31 BO 3 (M + ): Found: t-Butyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3,6,7-tetrahydrooxepine (13c). NMR (CDCl 3 ) δ 0.91 (s, 9H), 1.24 (s, 6H), 1.26 (s, 6H), (m, 2H), (m, 1H), 2.60 (d, J = 15.9 Hz, 1H), 2.87 (d, J = 9.6 Hz, 1H), 3.37 (ddd, J = 1.5, 10.2, 12.0 Hz, 1H), 4.01 (dt, J = 4.2, 12.0 Hz, 1H), 6.74 (dt, J = 3.6, 7.2 Hzz, 1H); 13 C NMR (CDCl 3 ) δ 24.6, 24.9, 26.2, 32.4, 33.8, 35.1, 69.1, 83.3, 88.6, 145.8; IR (neat) 2984, 1636, 1148, 862 cm -1. HRMS calcd. for C 16 H 29 BO 3 (M + ): Found: Phenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3,6,7-tetrahydrooxepine (13d). NMR (CDCl 3 ) δ 1.24 (s, 6H), 1.25 (s, 6H), (m, 1H), (m, 3H), 3.58 (ddd, J = 1.5, 1 H 1 H 1 H 7

8 10.8, 12.0 Hz, 1H), 4.13 (dt, J = 3.9, 12.0 Hz, 1H), 4.40 (dd, J = 4.8, 6.9 Hz, 1H), 6.85 (dd, J = 3.0, 6.9 Hz, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 24.67, 24.75, 34.0, 39.9, 68.8, 82.5, 83.5, 126.1, 127.2, 128.3, 144.0, 146.6; IR (KBr) 2984, 1636, 1326, 1142 cm -1. Anal. calcd. for C 18 H 25 BO 3 : C, 72.02; H, Found: C, 71.73; H, Benzyloxymethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3,6,7-tetrahydrooxepine (13e). 1 H NMR (CDCl 3 ) δ 1.25 (s, 12H), (m, 2H), (m, 2H), (m, 3H), (m, 1H), 4.06 (dt, J = 3.9, 12.0 Hz, 1H), 4.53 (d, J = 12.3 Hz, 1H), 4.61 (d, J = 12.3 Hz, 1H), 6.77 (dt, J = 3.6, 7.2 Hz, 1H), (m, 5H); 13 C NMR (CDCl 3 ) δ 24.68, 24.73, 33.8, 34.4, 68.6, 73.3, 73.8, 79.0, 83.4, 127.5, 127.8, 128.3, 138.4, IR (neat) 2988, 1742, 1636, 1148 cm -1. HRMS calcd. for C 20 H 29 BO 4 (M + ): Found: Synthesis of (E)-2-Hexyl-4-(propen-1-yl)-3,6-dihydro-2H-pyran (14) (Scheme 2). A mixture of Pd(PPh 3 ) 4 (6.3 mg, mmol), (E)-1-bromopropene (25 mg, 0.20 mmol), 12a (51 mg, 0.17 mmol), and NaOEt (20% in EtOH, 116 mg, 0.34 mmol) in benzene (0.7 ml) was stirred under reflux for 2.5 h. The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. The residue was subjected to silica gel column chromatography (hexane:etoac = 70/1) to give 14 (27 mg, 76%). 1 H NMR (CDCl 3 ) δ 0.88 (t, J = 6.9 Hz, 3H), (m, 10H), 1.76 (d, J = 6.0 Hz, 3H), (m, 1H), (m, 1H), (m, 1H), (m, 2H), 5.57 (s, 1H), 5.63 (dq, J = 6.0, 15.6 Hz, 1H), 6.06 (d, J = 15.6 Hz, 1H); 13 C NMR (CDCl 3 ) δ 14.0, 18.0, 22.5, 25.4, 29.3, 30.7, 31.8, 36.0, 66.0, 73.7, 122.8, 123.7, 132.9, 133.4; IR (neat) 2940, 1732, 1136, 966 cm -1. HRMS calcd. for C 14 H 24 O (M + ): Found: Hexyl-4-(4-nitrophenyl)-3,6-dihydro-2H-pyran (15) (Scheme 2). A mixture of Pd(PPh 3 ) 4 (6.3 mg, mmol), p-iodonitrobenzene (64 mg, 0.26 mmol), 12a (51 mg, 0.17 mmol), and NaOEt (20% in EtOH, 116 mg, 0.34 mmol) in benzene (0.7 ml) was stirred under reflux for 3 h. The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. The residue was subjected to preparative TLC (hexane:etoac = 9/1) to give 15 (36 mg, 75%). 1 H NMR (CDCl 3 ) δ 0.89 (t, J = 6.9 Hz, 3H), (m, 10H), (m, 2H), (m, 1H), (m, 2H), (m, 1H), (m, 2H), (m, 2H); 13 C NMR (CDCl 3 ) δ 14.0, 22.5, 25.4, 29.2, 31.7, 32.6, 35.8, 66.2, 73.8, 123.8, 125.4, 126.8, 132.9, 146.7, 146.9; IR (neat) 2936, 1596, 1522, 1346 cm -1. HRMS calcd. for C 17 H 23 NO 3 (M + ): Found: Hexyltetrahydropyran-4-one (16) (Scheme 2). A mixture of 12a (50 mg, 0.17 mmol) and trimethylamine oxide dihydrate (21 mg, 0.19 mmol) in diglyme (0.7 ml) was stirred at 160 C for 1 h. 8

9 The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. The residue was subjected to silica gel column chromatography (hexane ~ hexane:etoac = 12/1) to give 16 (24 mg, 78%). 1 H NMR (CDCl 3 ) δ 0.87 (t, J = 6.6 H, 3H), (m, 10H), (m, 3H), (m, 1H), (m, 1H), 3.63 (dt, J = 3.0, 12.3 Hz, 1H), 4.27 (ddd, J = 1.2, 7.5, 11.4 Hz, 1H); 13 C NMR (CDCl 3 ) δ 13.9, 22.5, 25.0, 29.0, 31.6, 36.3, 42.2, 48.4, 66.5, 78.2, 207.4; IR (neat) 2940, 1726, 1254, 1088 cm -1. HRMS calcd. for C 11 H 20 O 2 (M + ): Found: (2-Hexyl-3,6-dihydro-2H-pyran-4-yl)butan-2-one (17) (Scheme 2). A mixture of Rh(acac)(CO) 2 (1.3 mg, mmol), 1,4-bis(diphenylphosphino)butane (2.2 mg, mmol), 12a (50 mg, 0.17 mmol), and methyl vinyl ketone (14 mg, 0.20 mmol) in MeOH (0.6 ml) water (0.1 ml) was stirred at 50 C for 11h. The organic materials were extracted with EtOAc, and the extract was dried over Na 2 SO 4, filtered, and evaporated. The residue was subjected to silica gel column chromatography (hexane:etoac = 10/1) to give 17 (34 mg, 84%). 1 H NMR (CDCl 3 ) δ 0.87 (t, J = 6.9 Hz, 3H), (m, 10H), (m, 2H), 2.15 (s, 3H), 2.24 (t, J = 7.2 Hz, 2H), (m, 2H), (m, 1H), (m, 2H), 5.39 (s, 1H); 13 C NMR (CDCl 3 ) δ 14.0, 22.5, 25.3, 29.3, 29.8, 30.6, 31.7, 34.3, 35.9, 41.3, 65.8, 73.7, 119.9, 134.4, 208.4; IR (neat) 2940, 1724, 1368, 1134 cm -1. HRMS calcd. for C 15 H 26 O 2 (M + ): Found:

10 X-Ray Crystal Structure of 7. O B O O Crystal data for 7: crystal size mm (recrystallized from EtOH); monoclinic, space group P21/n (no. 14), Z = 4; a = (6), b = (4), c = (4) Å; β = (3) ; V = (1) Å 3, ρcalcd = g/cm 3 ; µ = cm -1 ; max. 2θ = 125 (CuKa, λ = Å, graphite monochrometor, ω/2θ-scan, T = 293 K); 4074 reflections measured, 2885 independent, 1723 included in the refinement, Lorentzian polarization; direct method, anisotropical refinement for nonhydrogen atoms by full-matrix least-squares against F 2 with program package CrystanG (Mac Science), 279 parameters; R = 0.105, Rw = All hydrogen atoms were included in the refinement at the calculated positions (0.96 Å) with isotropic thermal parameters. The final structure contains some abnormal atom distances and angles on the tetramethyldioxaborolanyl group. This may be attributed to atomic disorder or considerable thermal vibration of those atoms in the crystal. 10

11 GEOMETRY TABLES for COMPOUND 7 FRACTIONAL ATOMIC COORDINATES & U(iso) Atom x/a y/b z/c U(iso) O(1) (3) (5) (3) 0.107(3) O(2) (3) (5) (4) 0.116(4) C(3) (5) (8) (5) 0.089(5) C(4) (5) (10) (5) 0.107(6) O(5) (5) (6) (4) 0.139(5) C(6) (4) (7) (5) 0.082(4) C(7) (5) (9) (6) 0.102(6) C(8) (7) (10) (7) 0.154(9) C(9) (6) (9) (6) 0.099(6) C(10) (6) (9) (7) 0.102(6) C(11) (6) (12) (6) 0.126(8) C(12) (6) (11) (7) 0.122(7) C(13) (9) (11) (10) 0.128(8) C(14) (7) (9) (7) 0.121(7) C(15) (6) (14) (7) 0.125(8) B(16) (5) (7) (5) 0.074(5) C(17) (6) (10) (6) 0.131(7) C(18) (15) (15) (11) 0.22(2) C(19) (11) (20) (8) 0.19(2) C(20) (9) (15) (8) 0.157(9) C(21) (15) (21) (9) 0.22(2) C(22) (11) (22) (13) 0.23(1) C(23) (7) (12) (9) 0.140(8) C(24) (11) (19) (11) 0.22(1) C(25) (15) (27) (14) 0.34(3) C(26) (8) (13) (9) 0.132(9) C(27) (18) (18) (15) 0.26(2) Temperature factor of the form: exp[-2pi^2u], U=U(iso) or 1/3 SUM(i)SUM(j){U(ij)*astar(i).astar(j).a(i).a(j).cos(ij)} ANISOTROPIC THERMAL PARAMETERS Atom U11 U22 U33 U12 U13 U O(1) 0.112(4) 0.125(4) 0.072(3) 0.051(3) (3) (3) O(2) 0.113(4) 0.147(5) 0.075(3) 0.059(4) (3) (3) C(3) 0.092(5) 0.110(7) 0.057(4) 0.022(5) (4) (4) C(4) 0.099(5) 0.158(8) 0.056(4) 0.054(6) (4) (5) O(5) 0.171(6) 0.160(6) 0.080(4) 0.067(5) 0.016(4) 0.035(3) C(6) 0.079(4) 0.095(5) 0.065(4) 0.020(4) (3) (3) C(7) 0.105(6) 0.132(7) 0.062(4) 0.055(5) (4) (4) C(8) 0.176(9) 0.187(11) 0.079(5) 0.086(9) (6) (6) C(9) 0.099(6) 0.120(8) 0.072(4) 0.004(5) 0.003(4) (5) 11

12 C(10) 0.088(6) 0.110(7) 0.095(6) 0.019(5) (4) (5) C(11) 0.122(7) 0.192(10) 0.061(4) 0.040(8) 0.018(5) 0.004(5) C(12) 0.102(6) 0.167(9) 0.088(6) 0.051(7) (5) (6) C(13) 0.123(9) 0.130(10) 0.116(8) 0.021(8) (7) (7) C(14) 0.149(8) 0.134(8) 0.075(5) 0.049(7) 0.022(6) 0.017(5) C(15) 0.106(7) 0.182(12) 0.083(5) 0.011(8) 0.010(5) (7) B(16) 0.077(5) 0.085(5) 0.056(4) 0.025(4) 0.003(3) 0.000(4) C(17) 0.130(7) 0.168(9) 0.079(5) 0.066(7) (5) (6) C(18) 0.33(2) 0.21(1) 0.11(1) 0.16(2) 0.06(1) 0.07(1) C(19) 0.21(1) 0.28(2) 0.07(1) 0.12(2) 0.02(1) -0.01(1) C(20) 0.159(9) 0.189(13) 0.105(7) 0.085(9) (7) (6) C(21) 0.31(2) 0.25(2) 0.09(1) 0.11(2) 0.04(1) 0.01(1) C(22) 0.19(1) 0.35(2) 0.14(1) -0.08(1) 0.00(1) 0.13(1) C(23) 0.113(7) 0.150(9) 0.143(9) 0.035(8) (7) (7) C(24) 0.22(2) 0.26(2) 0.14(1) 0.13(1) -0.09(1) -0.11(1) C(25) 0.30(2) 0.51(3) 0.18(1) -0.30(2) -0.08(2) 0.16(2) C(26) 0.135(9) 0.142(10) 0.107(7) (9) (6) 0.020(7) C(27) 0.40(3) 0.22(2) 0.15(1) 0.16(2) 0.03(2) 0.06(1) T=exp[-2pi**2(U11.h**2.astar**2+U22.k**2.bstar**2+ U33.l**2.cstar**2 +2U12.h.k.astar.bstar +2U13.h.l.astar.cstar+2U23.k.l.bstar.cstar)] INTRAMOLECULAR BOND LENGTHS (H omitted) Bond length limits based on covalent radii O(1) - B(16) 1.318(9) O(1) - C(17) 1.466(10) O(2) - C(8) 1.464(11) O(2) - B(16) 1.318(10) C(3) - C(6) 1.514(11) C(3) - C(9) 1.362(12) C(3) - C(10) 1.412(14) C(4) - C(6) 1.561(10) C(4) - C(11) 1.536(15) C(4) - C(12) 1.517(16) O(5) - C(11) 1.438(14) O(5) - C(14) 1.406(11) C(6) - C(7) 1.548(12) C(6) - B(16) 1.594(10) C(7) - C(14) 1.499(14) C(8) - C(17) 1.366(15) C(8) - C(20) 1.418(19) C(9) - C(15) 1.374(16) C(10) - C(13) 1.400(16) C(10) - C(23) 1.502(15) C(11) - C(19) 1.554(16) C(12) - C(23) 1.492(17) C(13) - C(26) 1.371(19) C(14) - C(18) 1.54(3) C(15) - C(26) 1.38(3) C(17) - C(24) 1.39(2) C(18) - C(27) 1.22(3) C(19) - C(21) 1.38(3) INTRAMOLECULAR BOND ANGLES (H omitted) Bond length limits based on covalent radii B(16) - O(1) - C(17) 107.5(6) C(8) - O(2) - B(16) 107.7(7) C(6) - C(3) - C(9) 121.5(8) C(6) - C(3) - C(10) 121.0(7) C(9) - C(3) - C(10) 117.3(9) C(6) - C(4) - C(11) 110.6(8) C(6) - C(4) - C(12) 110.4(7) C(11) - C(4) - C(12) 116.7(8) 12

13 C(11) - O(5) - C(14) 113.1(7) C(3) - C(6) - C(4) 111.0(7) C(3) - C(6) - C(7) 112.3(7) C(3) - C(6) - B(16) 103.5(6) C(4) - C(6) - C(7) 106.0(6) C(4) - C(6) - B(16) 114.4(6) C(7) - C(6) - B(16) 109.8(6) C(6) - C(7) - C(14) 111.1(8) O(2) - C(8) - C(17) 105.8(9) O(2) - C(8) - C(20) 113.0(10) C(17) - C(8) - C(20) 130.6(9) C(3) - C(9) - C(15) 122.6(10) C(3) - C(10) - C(13) 119.6(9) C(3) - C(10) - C(23) 121.4(9) C(13) - C(10) - C(23) 118.9(10) C(4) - C(11) - O(5) 109.8(8) C(4) - C(11) - C(19) 120.2(12) O(5) - C(11) - C(19) 105.1(10) C(4) - C(12) - C(23) 110.8(9) C(10) - C(13) - C(26) 121.3(12) O(5) - C(14) - C(7) 112.2(8) O(5) - C(14) - C(18) 106.5(9) C(7) - C(14) - C(18) 113.5(12) C(9) - C(15) - C(26) 120.7(10) O(1) - B(16) - O(2) 111.7(6) O(1) - B(16) - C(6) 122.1(7) O(2) - B(16) - C(6) 126.1(7) O(1) - C(17) - C(8) 105.8(7) O(1) - C(17) - C(24) 112.5(10) C(8) - C(17) - C(24) 136.6(11) C(14) - C(18) - C(27) 125.0(16) C(11) - C(19) - C(21) 113.6(15) C(10) - C(23) - C(12) 115.5(10) C(13) - C(26) - C(15) 118.4(12)