Reaction Steps
A catalytic amount of Lindlar catalyst (ca. 200 mg) was added to a solution of alcohol 33 (4.18 g, 4.51 mmol) in toluene (100 mL). The flask was flushed with H2 via a balloon several times, then stirred under an atmosphere of H2 until starting material was consumed (usually 1 h) as indicated by TLC analysis. The mixture was filtered through a pad of Celite and concentrated under reduced pressure to afford the alkene 34 as a colorless oil (3.82 g, 91%): IR (CHCl3) 3436, 2954, 2926, 2855, 1461, 1378, 1252, 1061, 836, 773 cm−11; 1H NMR (300 MHz, CDCl3) δ 7.56 (m, 6H), 7.34 (m, 9H), 5.73 (m, 2H), 5.60 (t, J=10.3 Hz, 1H), 5.43 (dd, J=10.9, 8.4 Hz, 1H), 4.73 (m, 1H), 3.98 (q, J=5.0 Hz, 1H), 3.68 (d, J=4.1 Hz, 1H), 3.59 (dd, J=9.7, 4.7 Hz, 1H), 3.48 (m, 1H), 3.36 (dd, J=9.0, 7.3 Hz, 1H), 2.79 (m, 1H), 2.58 (m, 1H), 2.23 (br, 1H), 1.78 (m, 1H), 1.71 (m, 1H), 1.66 (m, 2H), 1.50 (m, 1H), 1.11 (d, J=6.8 Hz, 3H), 1.07 (d, J=6.8 Hz, 3H), 1.00 (m, 34H), 0.22 (s, 3H), 0.18 (s, 3H), 0.14 (s, 6H), 0.13 (s, 6H); 13C NMR (75 MHz, CDCl3) δ 144.3, 135.3, 134.6, 131.5, 128.7, 127.7, 127.0, 126.8, 86.8, 79.6, 73.0, 68.2, 65.0, 64.7, 42.0, 39.6, 38.0, 36.4, 34.9, 33.4, 26.2, 26.0, 25.9, 19.9, 18.4, 18.3, 18.1, 18.0, 15.2, 14.5, −3.4, −3.7, −4.2, −4.4, −4.5, −5.4; LRMS (ESI) 951.7 [M+Na]+, 413.3, 243.1; HRMS (ESI) calcd for C56H92O5Si3Na 951.6150 [M+Na]+, found 951.6172; [α]20D 1.0 (c 0.62, CHCl3).
