Reaction Steps
A solution of (3R)-(−)-3-(3-bromophenyl)-3-(7-benzyloxyindol-1-yl)propan-1-ol (5.10 g, 11.62 mmol) and 2,6-lutidine (1.24 g, 11.62 mmol) in dry dichloromethane (20.0 ml) was added dropwise to a magnetically stirred solution of trifluoromethanesulfonic anhydride (2.20 ml, 13.10 mmol) in dichloromethane (40.0 ml) at −10° C. under nitrogen over a 25 min. period. The resulting grey solution was stirred below −10° C. for 20 min., quenched with water (250 ml), extracted into dichloromethane (2×200 ml), the combined organic extracts were washed with water (200 ml), dried (Na2SO4) and the solvent removed in vacuo at room temperature to give an orange/brown oil which was dissolved in dry tetrahydrofuran (40.0 ml) and added dropwise to the stirred lithio acetonitrile reagent(52.19 mmol) in tetrahydrofuran at −70° C. TLC inspection immediately after the addition showed that the reaction was complete. Quenched with water (20.0 ml), diluted with ethyl acetate (300 ml), washed with brine (2×200 ml), dried (Na2SO4) and adsorbed onto silica (ca. 12.0 g). Column chromatography (ethyl acetate-light petroleum (b.p. 40-60° C.), 1:4) gave the title compound as a pale yellow oil (4.17 g, 78%). (Found: C, 67.62; H, 5.04; N, 5.94; Br, 17.60. C26H23BrN2O requires C, 67.98; H, 5.05; N, 6.10; Br, 17.39%); [α]D19 −138 (c=0.010 gml−1 , CHCl3); νmax (thin film)/cm−1 3064, 2934, 2871, 2246.5 (CN), 1575; δH (270 MHz) 1.55 (2H, m, 2×butyl 3-H); 2.23 (2H, t, 2×butyl 4-H, 3J4,3=6.9 Hz); 2.30 (2H, m, 2×butyl 2-H); 5.17 (2H, q, CH2Ph, 2J=10.9 Hz); 6.35 (1H, dd, butyl 1-H, 3J1,2=9.7, 3J1,2=5.8 Hz); 6.56 (1H, d, 3-H, 3J2,2=3.3 Hz); 6.74 (1H, d, 6-H, Jo=7.9 Hz); 6.95 (1H, d, 4-H, Jo=7.9 Hz); 7.00 (1H, t, 5-H, Jo=7.9 Hz); 7.08 (1H, t, 5′-H, Jo=7.9 Hz); 7.14 (1H, d, 2-H, 3J3,2=3.3 Hz); 7.21 (1H, d, 6′-H, Jo=8.9 Hz); 7.25 (1H, t, 2′-H, Jm=1.1 Hz); 7.34 (1H, dd, 4′-H, Jo=8.4, Jm=1.5 Hz); 7.42 (5H, m, 5ArH). δC (67.8 MHz) 16.5 (butyl 3-C); 22.3 (butyl 4-C); 34.4 (butyl 2-C); 58.8 (butyl 1-C); 70.6 (PhCH2); 103.5 (indole 3-C); 104.1 (indole 6-C); 114.2 (indole 4-C); 119.1 (CN); 120.2 (indole 5-C); 122.6 (3′-C); 124.5 (indole 2-C); 125.0 (6′-C); 130.7 (1′-C); 136.5 (benzyl ipso-C); 144.2 (indole 7a-C); 147.0 (indole 7-C). The remaining signals lie between 128.2-130.6 ppm and cannot be assigned with any certainty; m/z 460.1, 458.1 (3.43, 3.32), 369.1, 367.1 (1.79, 1.66), 239.0, 237.0 (7.01, 7.72), 171.0, 169.0 (26.03, 26.07), 143.1 (100), 132.1 (6.44), 116.0 (9.37).
