Catalytic Asymmetric Synthesis of Alkyl Substituted Lactones by Enantioselective and Chemoselective Alkylation of Formylesters with Dialkylzincs Using N,N-Dibutylnorephedrine

Abstract
Optically active 4-alkyl-γ-butyrolactones and 5-alkyl-δ-valerolactones were obtained in high enantiomeric excesses (85–95% e.e.) from the catalytic asymmetric alkylation of 3- and 4-formylesters with dialkylzincs using N,N-dibutylnorephedrine as catalyst.