The synthesis of (±)-pulvilloric acid and of (±) methyl dihydropul-villorate

Abstract

3,5-Dimethoxyphenylacetyl chloride has been converted into 1-(3,5-dimethyoxyphenyl)heptan-2-one, and thence by demethylation into 1-(3,5-dihydroxyphenyl)heptan-2-one. Reduction of the latter with sodium borohydride, followed by carboxylation, gave (±)-1-(4-carboxy-3,5-dihydroxyphenyl)-heptan-2-ol. This reacted readily with ethyl orthoformate to give (±)-pulvilloric acid. Carboxylation of the (+)-heptan-2-ol followed by esterification with diazomethane and treatment with dimethoxymethane gave a very low yield of (±)-methyl dihydropulvillorate.

Several other compounds are described which were obtained during a study of alternative routes to the above heptan-2-one and heptan-2-ol.