Diisopropylamine → HCID 178455043, compound

Participants

Reaction Conditions

Reaction Steps

A 2.5 M n-butyllithium solution in hexane (0.49 ml, 1.22 mmol) was added to a solution of diisopropylamine (0.18 ml, 1.29 mmol) in anhydrous THF (3.0 ml) at −78° C. under an argon stream. The mixture was brought to 0° C., and the mixture was stirred for 30 min and was again cooled to −78° C. A solution of benzyl 3-(4-((tert-butyldimethylsilyl)oxy)phenyl)propanoate (300 mg, 0.81 mmol) in anhydrous THF (4.0 ml) was added dropwise thereto at −78° C., and the mixture was stirred for additional one hr. A solution of benzyl 2-(cis-4-((tert-butyldimethylsilyl)oxy)cyclohexyl)-2-oxoacetate (304 mg, 0.81 mmol) in anhydrous THF (4.0 ml) that had been cooled to −78° C. was added through a cannula to the resultant enolate solution over 10 min. The mixture was stirred at −78° C. for one hr, was quenched and adjusted to pH 4 with acetic acid and was allowed to cool to room temperature. The reaction solvent was removed by distillation under reduced pressure, and the residue was diluted with ethyl acetate, and the diluted solution was washed with water and saturated brine and was dried over anhydrous magnesium sulfate. The filtrate was concentrated under reduced pressure. The residue was chromatographed on silica gel column (hexane:ethyl acetate=95:5) to give the title compound as an oil (a diastereomeric mixture; 120 mg, yield 19%).

Provenance & Evidence