Synthesis of Z-rethrolones and Z-rethrones

Abstract

Convenient syntheses of (Z)-jasmone {3-methyl-2-[(Z)-pent-2-enyl]cyclopent-2-enone}(2c), (Z)-cinerone {2-[(Z)-but-2-enyl]-3-methylcyclopent-2-enone}(2b), (±)-(Z)-jasmololone {(±)-4-hydroxy-3-methyl-2-[(Z)-pent-2-enyl]cyclopent-2-enone}(1c), and (±)-(Z)-cinerolone {(±)-4-hydroxy-3-methyl-2-[(Z)-but-2-enyl]-cyclopent-2-enone}(1b) from readily available allethrolone [4-hydroxy-3-methyl-2-(prop-2-enyl)cyclopent-2-enone](1a) are described. The route from (1a) to (1b and c) and (2b and c) is especially useful for the introduction of radio-labels into these compounds.