反应详情

Sodium borohydride (1.05 g, 27.7 mmol) was added portion wise to a stirred solution of tert-butyl 5-biphenyl-4-yl-2-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-3-oxopentanoate (12.1 g, 25.2 mmol) in methanol (80 mL) at 0° C. under nitrogen. On completion of addition stirring was continued for 1.5 h then the reaction was quenched with saturated aqueous ammonium chloride solution (80 mL). The resulting mixture was extracted with diethyl ether (3×200 mL) then the organic layers were combined, washed with brine (100 mL), dried (magnesium sulfate) and the solvent evaporated. The residue was chromatographed on silica gel (10% to 50% diethyl ether:cyclohexane) to give the title compound (8.47 g, 69%) as a colourless oil which was a mixture of diastereomers. LC/MS: 4.49 min; z/e 485, calcd (M+1) 485. 1H NMR (400 MHz: CDCl3): 7.60 (2H), 7.50 (2H), 7.45 (2H), 3.90 (1H minor), 3.80 (1H minor), 3.70 (1H major), 3.65 (1H major), 3.25 (1H minor), 3.00 (1H major), 2.90 (1H), 2.75 (1H), 2.60 (1H major), 2.55 (1H minor), 1.90 (1H), 1.85 (2H), 1.45 (10H), 0.90 (9H), 0.5 (6H).

1. additionOn completion of addition
2. customthe reaction was quenched with saturated aqueous ammonium chloride solution (80 mL)
3. extractionThe resulting mixture was extracted with diethyl ether (3×200 mL)
4. washwashed with brine (100 mL)
5. dry with materialdried (magnesium sulfate)
6. customthe solvent evaporated
7. customThe residue was chromatographed on silica gel (10% to 50% diethyl ether:cyclohexane)