Stereospecific Epoxidation of 4-Hydroxycyclopent-2-enones

Abstract

The treatment of 4,5-dialkyl-4-hydroxy-6-cyclopent-2-en-1-ones with H2C2 and KOH gave in high yields 2,3-epoxy-2,3-dialkyl-4-hydroxycyclopentanones. Furthermore, only one stereoisomer, characterized by trans relationship between the hydroxy group and the epoxide was obtained. This behaviour can be explained considering that epoxidation occurs during a base catalyzed transposition of the starting cyclopentenone.