One-pot Synthesis of Cyclopropane Derivatives with a Cis:Trans Stereoselectivity by Wittig Olefination-Sulfur Ylide Cyclopropanation Sequence

Abstract

Cyclopropane derivatives were synthesised in one pot from aromatic aldehydes, phenacyltriphenylphosphonium bromide, and S-phenacylthiolanium bromide by a Wittig olefination-sulfur ylide cyclopropanation sequence. When Cs2CO3 was used as the base and CH3CN/water (8:2, v/v) as the solvent, the major product was the cis-1,2-dibenzoyl cyclopropane. In contrast, when using DBU as the base and MeOH as the solvent, the major product was trans-dibenzoyl cyclopropane. In some cases, the major isomer was obtained in high purity and good yield by simple filtration.