Reaction Steps
The ester 96 (0.15 g, 0.14 μmol) was added to CH2Cl2 (5 mL) and H2O (0.2 mL) and DDQ (34 mg, 0.15 μmol) was added at 0° C. After 1 h of stirring at 0° C., the reaction mixture was quenched by adding sat'd NaHCO3 (5 mL). The organic phase was washed by sat'd NaHCO3 solution (3×10 mL) and brine, dried over MgSO4 and concentrated. Purification by flash column chromatography (EtOAc/hexane 1:9) furnished 97 (0.12 g, 90%) as a colorless oil: IR (CHCl3) 3540, 2956, 2929, 2856, 1641, 1601, 1471, 1462, 1407, 1379, 1361, 1255, 1174, 1089, 1004, 836, 773 cm−1; 1H NMR (300 MHz, CDCl3) δ 7.33 (dd, J=15.5, 11.2 Hz, 1H), 6.61 (ddd, J=16.9, 10.5, 10.4 Hz, 1H), 6.51 (t, J=11.4 Hz, 1H), 6.17 (dd, J=15.5, 5.9 Hz, 1H), 6.07 (t, J=11.0 Hz, 1H), 5.54 (d, J=11.3 Hz, 1H), 5.45-5.37 (m, 2H), 5.28 (m, 1H), 5.18 (d, J=16.8 Hz, 1H), 5.09 (d, J=10.1 Hz, 1H), 4.51 (m, 1H), 3.91 (m, 1H), 3.74 (m, 1H), 3.69 (s, 3H), 3.45 (m, 1H), 3.23 (m, 1H), 3.76 (m, 1H), 2.56 (m, 2H), 2.29 (br, 1H), 1.68 (m, 1H), 1.56-1.41 (m, 3H), 1.34-1.17 (m, 3H), 1.02 (d, J=6.9 Hz, 3H), 0.97 (d, J=6.9 Hz, 3H), 0.94 (d, J=6.8 Hz, 3H), 0.90-0.84 (m, 40H), 0.81 (d, J=5.8 Hz, 3H), 0.77 (d, J=6.5 Hz, 3H), 0.76 (d, J=6.2 Hz, 3H), 0.08-0.01 (m, 24H); 13C NMR (75 MHz, CDCl3) δ 166.8, 147.3, 145.5, 135.3, 133.0, 132.3, 131.5, 129.9, 126.4, 117.6, 115.2, 81.3, 77.5, 76.7, 72.7, 66.4, 50.9, 42.9, 42.6, 40.1, 37.9, 36.1, 35.4, 35.2, 33.8,.32.2, 30.6, 26.2, 26.0, 25.9, 19.6, 19.0, 18.4, 18.10, 18.05, 17.7, 16.6, 14.4, 6.9, −2.8, −3.5, −3.6, −3.7, −4.1, −4.15, −4.21, −4.4; LRMS (ESI) 1043.7 [M+Na]+, 889.8, 757.6, 625.5, 544.3, 364.4; HRMS (ESI) calcd for C57H112O7Si4Na 1043.7383 [M+Na]+, found 1043.7433; [α]20D−40.3 (c 2.1, CHCl3).
