(3R,5R)-3,5-Bis[(tert-butyldimethylsilyl)oxy]-1-hydroxy4-methylenecyclohexanecarboxylic Acid Methyl Ester → [(3R,5R)-3,5-Bis[(tert-butyldimethylsilyl)oxy]-1-hydroxy4-methylenecyclohexyl]methanol

Participants

Reaction Conditions

Reaction Steps

Diisobutylalurninum hydride (1.5 M in toluene, 2.0 mL, 3 mmol) was added to a solution of the ester 3 (215 mg, 0.5 mmol) in anhydrous ether (3 mL) at −78° C. under argon. The mixture was stirred at −78° C. for 3 h and at −24° C. for 1.5 h, diluted with ether (10 mL) and quenched by the slow addition of 2N potassium sodium tartrate. The solution was warmed to room temperature and stirred for 15 min, then poured into brine and extracted with ethyl acetate and ether. The organic extracts were combined, washed with diluted (ca. 1%) HCl, and brine, dried (MgSO4) and evaporated. The crystalline residue was purified by flash chromatography. Elution with hexane/ethyl acetate (9:1) gave crystalline diol 4 (43 mg, 24%).

Provenance & Evidence