Novel β-Masked Formylation of α,β-Unsaturated Ketones and Lactones by Tetra-n-Butylammonium Sulfate Radical

Abstract

Tetra-n-butylammonium peroxydisulfate was prepared and found to be a good source of tetra-n-butylammonium sulfate radical by its oxygen - oxygen bond cleavage. The sulfate radical can be utilized for the efficient organic synthesis in organic solvents. Electron deficient olefins such as α,β-unsaturated ketones or lactones were smoothly β-masked formylated by treatment of the olefins with 1,3-dioxolane in the presence of tetra-n-butylammonium peroxydisulfate. Extremely high diastereofacial selectivity (˜100% de) was obtained in β-masked formylation of α,β-unsaturated lactone, (S)-5-(t-butyldiphenyl silyloxymethyl)-2(5H)-furanose.