An asymmetric synthesis of esters and γ-lactones with simultaneous construction of vicinal stereogenic carbons at the α- and β-position starting from optically active 1-chlorovinyl p-tolyl sulfoxides

Abstract

Treatment of optically active 1-chlorovinyl p-tolyl sulfoxides with two different substituents at the 2-position, which were synthesized from aldehydes or unsymmetrical ketones and ( R)-(−)-chloromethyl p-tolyl sulfoxide in two or three steps, with the lithium enolate of carboxylic acid tert-butyl esters gave the adducts with substituents at the α- and β-position with high 1,3- and 1,4-chiral induction from the stereogenic sulfur center in high yields. The adducts were converted to optically active esters and γ-lactones having stereogenic centers at the α- and β-position in good to high yields. This procedure offers a new method for a synthesis of optically active carboxylic acid derivatives with stereogenic centers at the α- and β-position.