NOVEL ASYMMETRIC ALKYLATION OF CYCLIC β-KETO ESTERS WITH OPTICALLY ACTIVE SULFONIUM SALTS

Abstract A new asymmetric alkylation of cyclic β-keto esters with optically active sulfonium salts, which are easily prepared by optical resolution methods, has been investigated. Relative reactivities for alkyl substituents are found to be quite different from those for SN2 alkylation. Stereochemical reaction course via S–O sulfurane intermediate for this new reaction is proposed.