Efficient syntheses of four chiral phenylcyclopropanes

Abstract

An efficient four-step synthetic route from each of four crystalline isotopically labeled (1R)-menthyl (1S,2S)-(+)-2-phenylcyclopropanecarboxyates of better than 99% enantiomeric excess has provided multi-gram quantities of the corresponding chiral phenylcyclopropanes. The key transformation involved a bis[1,3-bis(diphenylphosphino)propane]rhodium chloride that catalyzed a highly stereoselective decarbonylation of a trans-2-phenylcyclopropanecarboxaldehyde.Key words: cyclopropanes chiral thanks to isotopic substituents, catalytic decarbonylations of cyclopropanecarboxaldehydes.