Reaction Steps
TBSOTf (2.08 mL, 9.07 mmol) was added to a stirred solution of the alcohol 34 (3.82 g, 4.11 mmol) and 2,6-lutidine (1.14 mL, 9.85 mmol) in CH2Cl2 (14 mL) at 0° C. The reaction mixture was stirred for 1 h at 0° C. The reaction mixture was quenched by the addition of H2O (25 mL). The reaction mixture was extracted with CH2Cl2 which was dried over MgSO4, filtered and the solvent was evaporated under reduced pressure. The residue was purified by short column chromatography (hexane/EtOAc 19:1) to obtain 35 (4.27 g, 99%) as a colorless oil: IR (CHCl3) 2956, 2929, 2856, 1471, 1462, 1449, 1255, 1089, 1005, 836, 773, 705 cm−1; 1H NMR (300 MHz, CDCl3) δ 7.60 (m, 6H), 7.39 (m, 9H), 5.77 (m, 2H), 5.56 (t, J=10.8 Hz, 1H), 5.42 (dd, J=11.0, 8.2 Hz, 1H), 4.69 (m, 1H), 4.07 (m, 1H), 3.71 (d, J=3.8 Hz, 2H), 3.64 (dd, J=9.8, 4.8 Hz, 1H), 3.53 (m, 1H), 3.40 (dd, J=9.6, 7.5 Hz, 1H), 2.74 (m, 1H), 2.55 (m, 1H), 1.89 (m, 3H), 1.59 (m, 3H), 1.12 (d, J=6.2 Hz, 6H), 1.04 (m, 42H), 0.26 (s, 3H), 0.24 (s, 3H), 0.19 (s, 6H), 0.18 (s, 3H), 0.17 (s, 6H), 0.16 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 144.4, 134.5, 132.9, 132.6, 128.7, 127.7, 126.8, 86.8, 79.9, 72.3, 68.3, 66.5, 65.1, 64.1, 42.4, 41.6, 37.9, 36.0, 35.3, 33.6, 26.3, 26.02, 25.97, 25.7, 19.4, 18.5, 18.4, 18.20, 18.15, 18.1, 15.5, 13.3, −2.9, −3.5, −3.7, −4.1, −4.2, −4.3, −5.3; LRMS (ESI) 1065.9 [M+Na]+, 413.3, 359.3, 328.3, 243.1; HRMS (ESI) calcd for C62H106O5Si4Na 1065.7015 [M+Na]+, found 1065.7026; [α]20D−10.4 (c 0.53, CHCl3).
