Facile access to chiral 5-hydroxy-2-methylhexanoic acid lactones (pheromones of the carpenter Bee)

Abstract

Alkyl 2-acyloxy-3-deoxy-D-erythro-hex-2-enopyranoside diesters are converted into the corresponding alkyl 2-C-methylene-3, 4-enopyranosides upon treatment with methylenetriphenylphosphorane and, depending on the nature of the aglycone, hydrogenation of the dienes can lead to 2-C-methyl derivatives with (R)- or (S)-stereochemistry, which can be easily converted into isomeric chiral 2,5-dimethylvalerolactones.