Reaction Steps
The procedure for 47 was used with 76 (0.38 g, 0.34 μmol) and DDQ (0.084 g, 0.37 mmol) to yield 77 (0.28 g, 82%) after flash column chromatography (EtOAc/hexane 1:9) as a colorless oil: IR (CHCl3) 3542, 2956, 2856, 1722, 1640, 1462, 1254, 1175, 1086, 1004, 836, 773 cm−1; 1H NMR (300 MHz, CDCl3) δ 7.39 (dd, J=15.2, 11.2 Hz, 1H), 6.63 (ddd, J=16.9, 10.5, 10.4 Hz, 1H), 6.53 (t, J=11.3 Hz, 1H), 6.09 (t, J=1.0 Hz, 1H), 5.98 (dd, J=8.3, 7.1 Hz, 1H), 5.58 (d, J=11.3 Hz, 1H), 5.45-5.39 (m, 2H), 5.26 (dd, J=10.8, 8.4 Hz, 1H), 5.20 (d, J=16.9 Hz, 1H), 5.11(d, J=10.1 Hz, 1H), 4.53 (m, 1H), 3.95 (m, 1H), 3.76 (m, 1H), 3.71 (s, 3H), 3.47 (m, 1H), 3.40 (m, 1H), 2.82 (m, 1H), 2.55 (m, 1H), 2.20 (br, 1H), 1.72 (m, 2H), 1.60-1.35 (m, 5H), 1.32-1.10 (m, 5H), 1.04 (d, J=6.8 Hz, 3H), 0.99-0.83 (m, 48H), 0.12-0.03 (m, 24H); 13C NMR (75 MHz, CDCl3) δ 166.7, 147.1, 145.4, 135.2, 132.6, 132.5, 132.3, 130.0, 126.8, 117.7, 115.5, 80.2, 77.3, 76.2, 72.1, 66.5, 50.9, 43.4, 42.5, 38.3, 38.1, 36.1, 35.8, 34.7, 33.7, 28.3, 26.2, 25.94, 25.89, 25.5, 19.5, 18.4, 18.1, 17.7, 14.9, 13.3, 7.2, −3.0, −3.6, −3.8, −4.18, −4.20, −4.37, −4.41; LRMS (ESI) 1029.7 [M+Na]+, 875.6, 379.3; HRMS (ESI) calcd for C56H110O7Si4Na 1029.7226 [M+Na]+, found 1029.7244; [α]20D−18.7 (c 0.62, CHCl3).
