Supporting Information. Table of Contents. II. Experimental procedures. II. Copies of 1H and 13C NMR spectra for all compounds

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1 Electronic upplementary Material (EI) for rganic & Biomolecular Chemistry. This journal is The Royal ociety of Chemistry 2017 Laboratoire de Méthodologie et ynthèse de Produit aturels. Université du Québec à Montréal, C.P.8888, ucc. Centre-Ville, Montréal. 3C 3P8, Québec, Canada. upporting Information Table of Contents I. General information I1 II. Experimental procedures I2-I8 II. Copies of 1 and 13C MR spectra for all compounds I9-I52 I. General information and materials Unless otherwise indicated, 1 and 13C MR spectra were recorded at 300 and 75 Mz, respectively, in CDCl3 solutions. Chemical shifts are reported in ppm on the δ scale. Multiplicities are described as s (singlet), d (doublet), dd, ddd, etc. (doublet of doublets, doublet of doublets of doublets, etc.), t (triplet), q (quartet), p (pentuplet), m (multiplet), and further qualified as app (apparent) br (broad) c (complex). Coupling constants, J, are reported in z. IR spectra (cm 1) were recorded from thin films. Mass spectra (m/e) were measured in the electrospray (EI) mode. -1-

2 II. Experimental procedures: a) General procedure for the formation of cycloadduct 6: A solution of (diacetoxyiodo)benzene («DIB», 0.5 mmol, 2.5 equiv.) in minimum of (CF 3 ) 2 C, was added dropwise on 30 second to a vigorously stirred solution of sulfonamide 3 (0.2 mmol, 1 equiv.), furan (4 mmol, 20 equiv.) and a 2 C 3 in a minimum of FIP at room temperature. The mixture was then stirred for 5 minutes (the reaction was followed by TLC) and quenched with a saturated ac 3 solution. The phases were separated and the aqueous phase extracted with C 2 Cl 2. The organic layers was washed with a saturated acl solution. Then, the organic phases were dried over a 2 4, filtered and concentrated under vacuum. The residue was purified by silica gel chromatography with a mixture of C 2 Cl 2 /hexane excepted for compounds 6ah, 6ai, 6aj and 6j (mixture of ethyl acetate/hexane) with 2% 4 to give the corresponding cycloaddition product 6. 7-methyl-4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6a): was obtained as a pale yellow oil: 0.1 mmol, 25.0 mg, 50% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.34 (d, J = 8.3 z, 1), 7.29 (s, 1), 7.17 (d, J = 7.8 z, 1), 6.55 (d, J = 1.6 z, 1), 6.01 (d, J = 9.0 z, 1), (m, 1), 5.37 (t, J = 2.6 z, 1), 2.90 (s, 3), 2.33 (s, J = 9.2 z, 3); 13 C MR (75 Mz, CDCl 3 ) δ 149.8, 139.0, 133.9, 13, 129.1, 127.4, 113.9, 100.2, 83.4, 70.3, 37.7, 2; RM (EI): Calc. for C a 3 (M+a) + : ; found: methyl-4-tosyl-4,8b-dihydro-3a-furo[3,2-b]indole (6ah): The desired compound was obtained as a yellow oil: 0.06 mmol, 18 mg, 27% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.64 (d, J = 8.3 z, 2), 7.54 (d, J = 8.8 z, 1), 7.21 (d, J = 8.1 z, 2), 7.15 (m, 2), 6.46 (br, 1), 5.76 (d, J = 8.9 z, 1), (m, 1), 5.35 (t, J = 2.6 z, 1), 2.36 (s, 3), 2.30 (s, 2); 13 C MR (75 Mz, CDCl 3 ) δ 149.0, 144.2, 139.2, 135.0, 134.2, 131.7, 129.8, 127.3, 127.0, 115.6, 101.4, 83.3, 70.1, 31.1, 29.9, 21.7, 2; RM (EI): Calc. for C (M+) + : ; found: methyl-4-((2-nitrophenyl)sulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6ai): (0.1 mmol tart), the desired compound was obtained as a pale red oil: mmol, 1 mg, 30% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.88 (d, J = 8.0 z, 1), (m, 2), 7.59 (dd, J = 14.7, 7.1 z, 1), 7.32 (d, J = 8.3 z, 1), 7.26 (s, 1 under CDCl 3 ), 7.13 (d, J = 8.3 z, 1), 6.51 (br, 1), 6.00 (d, J = 9.0 z, 1), 5.76 (d, J = 8.8 z, 1), 5.30 (br, 1), 2.33 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 149.5, 138.2, 134.6, 134.1, 132.3, 131.8, 131.8, 130.2, 129.6, 127.3, 124.5, 114.6, 10, 83.1, 77.4,70.6, 2; RM (EI): Calc. for C (M+ 4 ) + : ; found:

3 4-(methylsulfonyl)-7-propyl-4,8b-dihydro-3a-furo[3,2-b]indole (6b): was obtained as an orange solid: mmol, 2 mg, 41% yield; 1 MR (300 Mz, CDCl 3 ) δ 1 MR (300 Mz, CDCl 3 ) δ 7.35 (d, J = 8.3 z, 1), 7.29 (s, 1), 7.17 (dd, J = 8.3, 1.4 z, 1), 6.55 (d, J = 1.6 z, 1), 6.02 (d, J = 9.0 z, 1), 5.54 (ddd, J = 9.0, 2.4, 1.2 z, 1), 5.38 (t, J = 2.6 z, 1), 2.90 (s, 3), 2.57 (t, J = 7.4 z, 2), 1.62 (m, 2), 4 (t, J = 7.3 z, 3); 13 C MR (75 Mz, CDCl 3 ) δ 149.9, 139.2, 138.8, 131.5, 128.9, 126.8, 113.8, 100.2, 83.5, 70.3, 37.8, 37.5, 24.7, 13.9; RM (EI): Calc. for C (M+) + : ; found: isopropyl-4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6c): was obtained as a pale orange/brown oil: mmol, 24.7 mg, 45% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.37 (s, 1), 7.35 (s, 1), 7.22 (dd, J = 8.4, 1.7 z, 1), 6.56 (d, J = 1.6 z, 1), 6.03 (d, J = 9.0 z, 1), (m, 1), 5.38 (t, J = 2.6 z, 1), 2.90 (br, 3 + 1), 1.25 (d, J = 6.9 z, 6); 13 C MR (75 Mz, CDCl 3 ) δ 149.9, 145.1, 139.3, 129.6, 128.9, 124.7, 113.9, 100.2, 83.6, 70.3, 37.9, 33.7, 24.3, 24.1; RM (EI): Calc. for C (M+) + : ; found: (methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6d): was obtained as a pale yellow solid: mmol, 15.1 mg, 32% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.45 (m, 2), 7.38 (td, J = 7.4, 1.1 z 1), 7.12 (td, J = 7.4, z, 1), 6.57 (dd, J = 2.6, z, 1), 6.05 (d, J = 9.1 z, 1), 5.57 (ddd, J = 9.0, 2.4, 1.2 z, 1), 5.40 (t, J = 2.6 z, 1), 2.93 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 150.1, 141.3, 131.4, 128.7, 127.1, 124.0, 113.9, 100.1, 83.4, 70.2, 37.9; RM (EI): Calc. for C (M+ 4 ) + : ; found: (3aR,8bR)-7-methyl-4-(pyrrolidin-1-ylsulfonyl)-4,8b-dihydro-3a-furo[3,2- b]indole (6aj) (0.125 mmol start): was obtained as a pale yellow oil: mmol, 19.0 mg, 50% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.24 (s, 1), 7.19 (d, J = 8.3 z, 1), 7.12 (d, J = 8.3, 1), 6.52 (dd, J = 2.6, 1.1 z, 1), 6.01 (d, J = 9.1 z, 1), 5.59 (ddd, J = 9.1, 2.5, 1.3 z, 1), 5.36 (t, J = 2.6 z, 1), (m, 4), 2.32 (s, 3), (m, 4); 13 C MR (75 Mz, CDCl 3 ) δ 149.3, 139.8, 132.9, 131.6, 128.7, 127.0, 114.0, 101.3, 83.6, 70.5, 48.3, 25.7, 2; RM (EI): Calc. for C (M+) + : ; found:

4 Cl 7-chloro-4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6e): (0.1 mmol tart): the desired compound was obtained as a pale orange oil: mmol, 13.4 mg, 50% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.45 (s, 1), 7.39 (d, J = 8.6 z, 1), 7.32 (d, J = 8.7 z, 1), 6.57 (br, 1), 6.00 (d, J = 9.0 z, 1), 5.59 (d, J = 9.1 z, 1), 5.39 (br, 1), 2.92 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 150.1, 140.0, 131.3, 130.7, 129.2, 127.2, 115.0, 100.1, 82.7, 70.6, 38.3; RM (EI): Calc. for C Cl 3 (M+) + : 27143; found: Br 7-bromo-4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6f): (0.1 mmol tart), the desired compound was obtained as a yellow solid: mmol, 11 mg, 35% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.60 (d, J = 1.9 z, 1), 7.47 (dd, J = 8.7, z, 1), 7.33 (d, J = 8.7 z, 1), 6.57 (dd, J = 2.6, z, 1), 6.00 (d, J = 9.1 z, 1), 5.58 (ddd, J = 9.1, 2.5, 1.3 z, 1), 5.39 (t, J = 2.6 z, 1), 2.93 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 150.1, 140.6, 134.2, 13, 130.2, 116.3, 115.4, 100.0, 82.6, 70.6, 38.3; RM (EI): Calc. for C Br 2 3 (M+ 4 ) + : ; found: Me 7-methoxy-4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6g): was obtained as a pale yellow oil: mmol, 24.9 mg, 47% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.39 (d, J = 8.9 z, 1), 7.02 (d, J = 2.6 z, 1), 6.92 (dd, J = 8.9, 2.6 z, 1), 6.55 (dd, J = 2.5, 1.1 z, 1), 6.02 (d, J = 9.1 z, 1), 5.55 (ddd, J = 9.0, 2.4, 1.3 z, 1), 5.37 (t, J = 2.6 z, 1), 3.81 (s, 3), 2.87 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 157.0, 149.6, 134.7, 130.3, 117.5, 115.4, 111.7, 100.4, 83.4, 70.5, 55.9, 37.2; RM (EI): Calc. for C a 4 (M+a) + : ; found: Me 2 C Methyl 2-(4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indol-7- yl)acetate (6h): (0.1 mmol tart), the desired compound was obtained as a pale orange oil: mmol, 14.0 mg, 45% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.39 (d, J = 5.2 z, 2), 7.28 (s, J = 7.3 z, 1), 6.55 (br, 1), 6.02 (d, J = 9.0 z, 1), 5.56 (d, J = 8.9 z, 1), 5.38 (br, 1), 3.70 (s, 3), 3.61 (s, 2), 2.92 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 17, 150.0, 140.5, 132.4, 129.8, 129.3, 127.9, 114.0, 100.2, 83.2, 70.4, 52.3, 40.5, 38.1; RM (EI): Calc. for C (M+ 4 ) + : ; found:

5 i 4-(methylsulfonyl)-7-(trimethylsilyl)-4,8b-dihydro-3a-furo[3,2-b]indole (6i): (0.082 mmol tart), the desired compound was obtained as a pale yellow oil: mmol, 13.6 mg, 54% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.63 (s, 1), 7.51 (d, J = 8.1 z, 1), 7.43 (d, J = 8.1 z, 1), 6.57 (br, 1), 6.05 (d, J = 9.0 z, 1), 5.56 (d, J = 9.1 z, 1), 5.40 (br, 1), 2.91 (s, 3), 0.27 (s, 9); 13 C MR (75 Mz, CDCl 3 ) δ 150.3, 142.3, 136.8, 136.2, 132.2, 128.6, 113.6, 100.4, 83.8, 70.4, 38.6, -0.6 (3xC*i); RM (EI): Calc. for C i (M+) + : ; found: Br Me 7-(methylsulfonyl)-7a,10a-dihydro-7-benzo[e]furo[3,2-b]indole (12a): was obtained as a pale yellow oil: (0.047 mmol tart), the desired compound was obtained as a yellow oil: mmol, 6 mg, 47% yield (ratio 4:1); 1 MR (300 Mz, Acetone) δ 7.39 (d, J = 8.4 z, 1), 6.99 (d, J = 2.3 z, 1), 6.70 (dd, J = 8.4, 2.3 z, 1), 6.66 (dd, J = 2.6, z, 1), 6.06 (d, J = 8.9 z, 1), 5.64 (ddd, J = 8.9, 2.5, 1.3 z, 1), 5.28 (t, J = 2.6 z, 1), 3.81 (s, 3), 0 (s, 3); 13 C MR (75 Mz, Acetone) δ 163.2, 150.6, 128.7, 122.2, 110.5, 101.6, 100.7, 84.1, 71.9, 56.0, 37.3; RM (EI): Calc. for C (M+) + : ; found: (4-(pyrrolidin-1-ylsulfonyl)-4,8b-dihydro-3a-furo[3,2-b]indol-7- yl)ethanol (6j): (0.043 mmol tart), the desired compound was obtained as a yellow oil: mmol, 7.5 mg, 51% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.31 (s, 1), 7.20 (m, 2), 6.53 (d, J = 1.6 z, 1), 6.02 (d, J = 9.1 z, 1), (m, 1), 5.37 (t, J = 2.6 z, 1), 3.85 (t, J = 6.5 z, 2), 3.35 (m, 4), 2.85 (t, J = 6.5 z, 2), (m, 4); 13 C MR (75 Mz, CDCl 3 ) δ 149.4, 133.5, 131.7, 129.0, 127.1, 114.2, 101.3, 83.5, 70.6, 63.8, 48.3, 38.6, 29.9, 25.8; RM (EI): Calc. for C (M+) + : ; found: Br 6-bromo-7-methyl-4-(methylsulfonyl)-4,8b-dihydro-3a-furo[3,2- b]indole (10a and 10b): The desired compound was obtained as an orange oil: 0.11 mmol, 36.4 mg, 55% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.64 (s, 1), 7.32 (m, 1), 7.27 (s, 1), 7.22 (m, 1), 6.61 (d, J = 1.9 z, 1), 6.55 (d, J = 1.6 z, 1), 6.06 (d, J = 9.1 z, 1), 5.95 (d, J = 9.0 z, 1), (m, 2), 5.42 (t, J = 2.6 z, 1), 5.37 (t, J = 2.6 z, 1), 2.92 (s, 3), 2.90 (s, 3), 2.37 (br, 3 + 3), 13 C MR (75 Mz, CDCl 3 ) δ 150.2, 150.0, 140.6, 140.3, 133.6, 133.5, 133.3, 129.2, 128.5, 128.3, 127.5, 123.9, 117.6, 112.5, 100.2, 100.0, 84.4, 82.9, 70.7, 70.0, 38.2, 38.0, 22.6, 21.9; RM (EI): Calc. for C Br 3 (M+) + : ; found:

6 7-(methylsulfonyl)-7a,10a-dihydro-7-benzo[e]furo[3,2-b]indole (15): was obtained as a pale yellow solid: mmol, 23.8 mg, 42% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.98 (d, J = 8.4 z, 1), 7.89 (dd, J = 1, 8.7 z, 2), 7.74 (d, J = 9.0 z, 1), 7.60 (t, J = 7.6 z, 1), 7.46 (t, J = 7.2 z, 1), 6.62 (br, 1), 6.55 (d, J = 9.3 z, 1), 5.75 (m, J = 9.2 z, 1), 5.46 (t, J = 2.6 z, 1), 2.95 (s, 3), 1.53; 13 C MR (75 Mz, CDCl 3 ) δ 150.1, 139.5, 132.7, 13, 13, 128.8, 128.2, 125.2, 123.2, 122.1, 114.2, 100.2, 83.2, 7, 38.5; RM (EI): Calc. for C (M+ 4 ) + : ; found: methyl-6-(methylsulfonyl)-6,10b-dihydro-5a-benzofuro[2,3-b]indole (16): The desired compound was obtained as yellow solid: 0.08 mmol, 24.1 mg, 40% yield; 1 MR (300 Mz, CDCl 3 ) δ 7.77 (d, J = 7.8 z, 1), (m, 2), (m, 2), 6.96 (t, J = 7.5 z, 1), 6.83 (d, J = 8.2 z, 1), 6.30 (d, J = 8.6 z, 1), 5.94 (d, J = 8.5 z, 1), 2.87 (s, 3), 2.36 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 159.4, 139.6, 134.5, 132.1, 13, 129.0, 127.8, 127.4, 124.4, 121.6, 114.6, 110.6, 84.9, 68.3, 37.5, 2; RM (EI): Calc. for C (M+ 4 ) + : ; found: methyl-1-(methylsulfonyl)-1-indole-2-carbaldehyde (19a): A solution of 6a (6.8 mg, mmol, 1.equiv.) in Me ( ml) at -78 C was bubbled with 3 for 2 minutes (followed by TLC). The resulting solution was then bubbled with argon for 5 minutes and allowed to warm to 0 C. PPh 3 (14.2 mg, mmol, 2 equiv.) was then added and the mixture was stirred at 0 C for 30 minutes and at room temperature for 5 minutes. The solvent was removed under reduced pressure. The residue was purified by silica gel chromatography with a mixture of ethyl acetate/hexane to give the corresponding product 19a in 63% yield (4.0 mg, mmol). 1 MR (300 Mz, CDCl 3 ) δ (s, 1), 7.98 (d, J = 8.7 z, 1), 7.51 (s, 1), 7.48 (s, 1), 7.37 (d, J = 8.7 z, 1), 3.34 (s, 3), 2.47 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 18, 137.9, 137.6, 134.7, 131.1, 128.1, 123.4, 121.4, 114.8, 4, 21.3; RM (EI): Calc. for C (M+) + : ; found: (2-hydroxyethyl)-5-methyl-1-(methylsulfonyl)indolin-3-ol (20a): To a solution of 6a (10.0 mg, 0.04 mmol, equiv.) in Me ( ml) was added Pd/C (0.004mol, 0.1 equiv.) under 2. The mixture was stirred overnight at room temperature and the reaction was controlled by Mass pectroscopy. After completion, the mixture was filtered through Celite and concentrated under vacuum. The residue was purified by silica gel chromatography with a mixture of ethyl acetate/hexane to afford 20a as yellow oil in 55% yield (6.0 mg, mmol). 1 MR (300 Mz, CDCl 3 ) δ 7.36 (d, J = 8.0 z, 1), 7.03 (d, J = 9.2 z, 2), 4.56 (q, J = 13.9, 9.3 z, 1), (m, 1), 3.65 (m, 1), 3.47 (dd, J = 16.3, 9.1 z, 1), 2.76 (s, 3), 2.68 (d, J = 16.3 z, 2), 2.32 (s, 3), (m, 2); -6-

7 13 C MR (75 Mz, CDCl 3 ) δ 138.2, 135.6, 132.4, 128.9, 126.4, 117.8, 59.6, 58.3, 39.4, 35.6, 35.5, 21.2; RM (EI): Calc. for C a 4 (M+a) + : ; found: Compounds 21a and 22a: Trifluoroacetic acid (0.2 mmol, 5.0 equiv.) was added to a solution of cycloaddition product 6a (0.04 mmol, equiv.) in DCM (0.1 M) at 0 C and the solution was vigorously stirred at room temperature. The mixture was followed by TLC and after 15 min the solution was evaporated under reduced pressure and purified by silica gel chromatography with ethyl acetate/hexane to give a mixture of two products 21a (33%) and 21b (60%) in 93% overall yield. 7-methyl-4-(methylsulfonyl)-3,4- dihydro-2-furo[3,2-b]indol-2-ol (21a) : The desired compound was obtained as yellow solid: mmol, 3.6 mg, 33% yield; 1 MR (300 Mz, Acetone) δ 7.75 (d, J = 8.5 z, 1), 7.48 (s, 1), 7.12 (d, J = 8.5 z, 1), 5.66 (d, J = 6.3 z, 1), 3.56 (dd, J = 17.5, 7.2 z, 1), 3.23 (d, J = 17.5 z 1), 2 (s, 3), 2.44 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 134.2, 134.0, , 127.5, 126.2, 118.4, 113.9, 65.8, 40.3, 30.1, 29.8, 21.5; RM (EI): Calc. for C (M+) - : ; found: (5-methyl-1-(methylsulfonyl)-1-indol-2-yl)acetaldehyde (22a): The desired compound was obtained as yellow oil: mmol, 6.0 mg, 60% yield; 2-(5-methyl-1-(methylsulfonyl)- 1-indol-2-yl)acetaldehyde (22a): 1 MR (300 Mz, Acetone-D6) δ 9.77 (s, 1), 7.80 (d, J = 8.5 z, 1), 7.39 (s, 1), 7.17 (d, J = 8.3 z, 1), 6.62 (s, 1), 4.19 (br, 2), 3.23 (s, 3), 2.40 (s, 3). 13 C MR (75 Mz, CDCl 3 ) δ 198.1, 135.2, 133.8, 132.6, 129.7, 126.5, 121.1, 113.7, 112.3, 44.2, 39.6, 21.6; RM (EI): Calc. for C (M+) + : 25689; found: Cl (2,3R)-3-hydroxy-7-methyl-4-(methylsulfonyl)-3,3a,4,8btetrahydro-2-furo[3,2-b]indol-2-yl 3-chlorobenzoate (23a): m-cpba (0.08 mmol, 2 equiv.) was added at 0 C to a solution of 6a (10.0 mg, 0.04 mmol) in DCM (0.4 ml). The mixture was stirred at room temperature during 1 hour (followed by TLC). The solution was diluted in DCM and was quenched with a saturated a solution, the organic layer was washed with a saturated ac 3 solution, and a saturated acl solution. Then, the organic phases were dried over a 2 4, filtered and concentrated under vacuum. The residue was purified by silica gel chromatography with a mixture of ethyl acetate/hexane to give the isomer alpha in 55% yield (9.2 mg, mmol) and isomer beta in 18% yield (73 % overall yield, ratio 3/1). 1 MR (300 Mz, CDCl 3 ) 7.42 (m, 3), 7.25 (m, 2), 7.16 (m, 2), 6.49 (s, 1), 6.10 (d, J = 7.5 z, 1), 4.93 (s, 1), 4.59 (d, J = 7.5 z, 1), 2.91 (s, 3), 2.25 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 163.9, 139.7, 134.8, 134.5, 133.5, 131.9, 13, 130.5, 129.6, 129.6, 128.0, 127.3, 113.8, 102.6, 83.7, 8, 71.6, 35.5, 2; RM (EI): Calc. for C Cl 2 6 (M+ 4 ) + : 44912; found:

8 Br Me III. Copies of 1 and 13 C MR spectra (2R,3R)-3-bromo-2-methoxy-7-methyl-4-(methylsulfonyl)-3,3a,4,8btetrahydro-2-furo[3,2-b]indole (24a): To a mixture of 6a (10.0 mg, 0.04 mmol, 1 equiv.) in Me (0.1 ml) and DCM (0.1 ml) was slowly added B (7.83 mg, mmol, 1.1 equiv.) at 0 C. The mixture was stirred to room temperature and the reaction was followed by TLC. After 1h30, the solution was washed with a saturated acl solution. The organic layers were combined and dried over a 2 4, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography with a mixture of ethyl acetate/hexane to give the isomer alpha in 43% yield (6.0 mg, mmol) and the beta in 15% yield. 1 MR (300 Mz, CDCl 3 ) δ 7.29 (s, 1), 7.24 (s, 1), 7.13 (d, J = 8.3 z, 1), 5.93 (d, J = 7.4 z, 1), 5.25 (s, 1), 4.85 (d, J = 7.4 z, 1), 4.65 (s, 1), 2.89 (s, 3 + 3), 2.34 (s, 3); 13 C MR (75 Mz, CDCl 3 ) δ 139.4, 133.9, 131.4, 130.4, 126.8, 113.3, 110.0, 81.9, 7, 54.5, 52.8, 36.2, 2; RM (EI): Calc. for C Bra 4 (M+a) + : ; found:

9 9 6a CDCl 3, 300 Mz

10 10 6a CDCl 3, 75 Mz

11 11 6ah CDCl 3, 300 Mz

12 12 CDCl 3, 75 Mz 6ah

13 13 CDCl 3, 300 Mz 6ai 2 2 grease

14 14 CDCl 3, 75 Mz 6ai

15 15 CDCl 3, 300 Mz 6aj

16 16 CDCl 3, 75 Mz 6aj

17 17 CDCl 3, 300 Mz 6b

18 18 6b CDCl 3, 75 Mz

19 19 6c CDCl 3, 300 Mz

20 20 CDCl 3, 75 Mz 6c

21 21 6d

22 22 CDCl 3, 300 Mz CDCl 3, 75 Mz 6d

23 23 CDCl 3, 300 Mz 6e Cl

24 24 CDCl 3, 75 Mz 6e Cl

25 25 CDCl 3, 300 Mz 6f Br

26 26 CDCl 3, 75 Mz 6f Br

27 f1 (ppm) 27 CDCl 3, 300 Mz 6f CY Br

28 28 CDCl 3, 300 Mz 6g Me

29 29 6g CDCl 3, 75 Mz Me

30 30 CDCl 3, 300 Mz C 2 Me 6h

31 31 6h CDCl 3, 75 Mz C 2 Me

32 32 CDCl 3, 300 Mz 6i TM

33 33 6i CDCl 3, 75 Mz TM

34 34 CDCl 3, 300 Mz 6j 2 grease

35 35 CDCl 3, 75 Mz 6j

36 Br Br + 10 CDCl 3, 300 Mz

37 37 10 CDCl 3, 75 Mz + Br Br

38 38 Me 12a Acetone-D6, 300 Mz

39 39 Me Acetone-D6, 75 Mz 12a

40 40 15 CDCl 3, 300 Mz

41 41 CDCl 3, 75 Mz

42 42 CDCl 3, 300 Mz

43 43 CDCl 3, 75 Mz

44 44 CDCl 3, 300 Mz 19a

45 45 CDCl 3, 75 Mz 19a

46 46 CDCl 3, 300 Mz 20a

47 47 CDCl 3, 75 Mz 20a

48 48 Acetone-D6, 300 Mz 21a

49 49 21a CDCl 3, 75 Mz

50 50 22a Acetone-D6, 300 Mz

51 51 CDCl 3, 75 Mz 22a

52 52 Cl 23a CDCl 3, 300 Mz

53 53 Cl CDCl 3,, 75 Mz 23a

54 54 Br Me CDCl 3, 300 Mz 24a

55 55 CDCl 3, 75 Mz Br Me 24a