Reaction Steps
To silyl protected indole B (724 mmol, 1.52 mmol) in THF was added a few 4 Å molecular sieves and the mixture was cooled to −78° C. After n-BuLi (0.75 ml, 2.3M in hexanes) was added, the mixture was stirred for 20 min and prenyl bromide (420 mmol, 2.82 mmol) was added. The next day the reaction mixture was quenched by addition of NH4Cl (sat), and extracted with Et2O. The combined organic layers were washed with brine, dried (MgSO4), and filtered, and the filtrated was concentrated in vacuo. Final purification by flash column chromatography (5% EtOAc in hexanes) afforded prenyl indole C (560 mg, 68%) as well as recovered starting material (76 mg, 10%): 1H NMR δ 7.91 (d, J=0.8 Hz, 1H), 7.73 (d, J=8.4 Hz, 2H), 7.25, (d, J=8.5 Hz, 2H), 6.99 (s, 1H), 6.52 (d, J=0.8 Hz, 1H), 5.47 (m, 1H), 5.31 (s, 2H), 4.90 (s, 2H), 3.74 (d, J=7.2 Hz, 2H), 3.55 (s, 3H), 2.40 (s, 3H), 1.86 (s, 3H), 1.71 (s, 3H) 1.05 (s, 9H), 0.20 (s, 6H); 13C NMR δ 149.5, 144.5, 139.9, 138.7, 138.6, 136.5, 134.5, 129.7 (2C), 126.3 (2C), 119.8, 119.6, 106.5, 106.3, 105.3, 94.8, 65.5, 56.0, 27.9, 25.9 (3C), 25.7, 21.4, 18.3, 17.7, −5.2 (2C); HRMS (EI+) calcd for C29H41NO5SSi [M+] 543.2475. found 543.2476.
