A New Synthetic Method of Methyl Ketones Part III

Syntheses of cis- and trans-Jasmone

Abstract

A simple and stereospecific method has been developed for the synthesis of cis-jasmone. 3-Methyl-2-cyclopentenone (V) was condensed with cis-2-pentenyl chloride, which was prepared from propargyl alcohol, by means of sodium amide in liquid ammonia to yield stereochemically pure cis-jasmone (VIb) in 39_??_40% yield. By the similar direct alkyla-tion, trans-jasmone (VIc) and dihydrojasmone (VIa) were also synthesized in moderate yields.