Reaction Steps
To a stirred solution of ester 91 (600 mg, 0.84 mmol) in CH2Cl2 (6 mL) at −40° C. under argon was added slowly over 10 min via syringe DibalH in toluene (9 mL, 1M). After 30 min at 40° C., the reaction mixture was quenched by slow addition of MeOH (0.6 mL) and warmed to rt. The reaction mixture was poured into a vigorously stirred solution of saturated Rochelle salt in H2O (8 mL) and EtOAc (12 mL) and stirred overnight. The aqueous layer was separated and extracted with EtOAc (3×5 mL), dried over MgSO4, filtered and concentrated in vacuo. The crude mixture was purified by flash chromatography (20% EtOAc in hexanes) to produce 450 mg (80%) of the alcohol, a clear liquid: 1H NMR (300 MHz, CDCl3) δ 7.70–7.66 (m, 4H), 7.39–7.35 (m, 6H), 7.21–7.18 (m, 4H), 6.85–6.82 (m, 4H), 5.68–5.65 (m, 2H), 4.64 (d, J=11.1 Hz, 1H), 4.51 (d, J=11.0 Hz, 1H), 4.46 (d, J=11.1 Hz, 1H), 4.24 (d, J=11.0 Hz, 1H), 4.10–4.06 (m, 2H), 3.78 (s, 6H), 3.81–3.52 (m, 4H), 2.60–2.56 (m, 1H), 1.57–1.51 (m, 2H), 1.05 (s, 9H), 1.03 (d, J=6.8 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 159.0, 135.6, 135.1, 133.5 (2C), 131.1, 130.3, 130.0, 127.6, 129.4, 129.6, 83.1, 75.2, 72.4, 72.2, 64.4, 63.7, 55.2, 34.7, 26.8, 19.2, 15.4; IR (thin film) 3295, 3045, 2958, 2941, 2910, 2857, 1241, 1097 cm−1; HRMS (EI) cald for C41H52O6Si 668.3599, found 668.3596.