PROCESS FOR PREPARING OPTICALLY ACTIVE 2-[6-(HYDROXY-METHYL)-1,3-DIOXAN-4-YL]ACETIC ACID DERIVATIVES

摘要

A process for preparing optically active 2-[6-(hydroxy-methyl)-1,3-dioxan-4-yl]acetic acid derivatives which comprises reacting an enolate prepared by reacting an acetic acid ester derivative with a base or a zero-valent metal with (S)- beta -hydroxy- gamma -butyrolactone at a temperature of -30 DEG C or above to thereby obtain a dihydroxyoxohexanoic acid derivative, treating this derivative with an acylating agent in the presence of a base to thereby obtain a monoacylated derivative of dihydroxyoxohexanoic acid, reducing the monoacylated derivative with a microorganism into a monoacylated derivative of trihydroxyhexanoic acid, treating the resulting derivative with an acetal-forming reactant in the presence of an acid catalyst to thereby obtain an acyloxymethyldioxanylacetic acid derivative, and subjecting this derivative to solvolysis in the presence of a base.