Preparation and diastereoisomerism of four substituted epoxycyclopentanones

Abstract

Abstract Epoxidation of 4‐acetoxy‐2‐(6′‐methoxycarbonylhexyl)‐2‐cyclopenten‐1‐one in alkaline medium yielded the two possible diastereoisomers of 2,3‐epoxy‐4‐hydroxy‐2‐(6′‐methoxycarbonylhexyl)‐1‐cyclopentanone. The structure and configuration of these compounds have been elucidated by first order analysis of the normal and spindecoupled proton magnetic resonance spectra. Both stereoisomeric epoxides can also be obtained via an alternative synthetic route by epoxidation of 2‐(6′‐carboxyhexyl)‐4‐hydroxy‐2‐cyclopenten‐1‐one. The separate cis and trans isomers of 2‐(6′‐carboxyhexyl)‐2,3‐epoxy‐4‐hydroxy‐1‐cyclopentanone are correlated with the stereoisomers of 2,3‐epoxy‐4‐hydroxy‐2‐(6′‐methoxycarbonylbexyl)‐1‐cyclopentanone by interconversion with diazomethane as well as by comparison of the proton spectra.