反应详情

Sodium borohydride (0.59 g, 15.6 mmol) was added portion wise to a stirred solution of 1,1-dimethylethyl 2-(2-{[(1,1-dimethylethyl)(dimethyl)silyl]oxy}ethyl)-5-(4-iodophenyl)-3-oxopentanoate (7.55 g, 14.2 mmol) in methanol (100 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 (100 mL). The resulting mixture was extracted with diethyl ether (3×200 mL) then the organic layers were combined, washed with brine (100 mL), dried (sodium sulfate) and the solvent evaporated. The residue was chromatographed on silica gel (25% to 50% diethyl ether: cyclohexane) to give the title compound (5.14 g, 68%) as a colourless oil which was a mixture of diastereomers. LC/MS: 4.72 min; z/e 535, calcd (M+1) 535. 1H NMR (400 MHz: CDCl3): 7.55 (2H), 6.95 (2H), 3.85-3.55 (3H), 3.30 (1H minor), 3.00 (1H major), 2.80 (1H), 2.65 (1H), 2.55 (1H major), 2.50 (1H minor), 1.95-1.65 (4H), 1.45 (9H), 0.90 (9H), 0.5 (6H).

1. additionOn completion of addition
2. customthe reaction was quenched with saturated aqueous ammonium chloride solution (100 mL)
3. extractionThe resulting mixture was extracted with diethyl ether (3×200 mL)
4. washwashed with brine (100 mL)
5. dry with materialdried (sodium sulfate)
6. customthe solvent evaporated
7. customThe residue was chromatographed on silica gel (25% to 50% diethyl ether: cyclohexane)