Enzymatic Resolution and Decarboxylative Functionalization of -Sulfinyl Esters

alpha-Sulfinyl esters can be readily prepared through thiol substitution of alpha-bromo esters followed by oxidation to the sulfoxide. Enzymatic resolution with lipoprotein lipase provides both the unreacted esters and corresponding alpha-sulfinyl carboxylic acids in high yields and enantiomeric ratios. Subsequent decarboxylative halogenation, dihalogenation, trihalogenation and cross-coupling gives rise to functionalized sulfoxides. The method has been applied to the asymmetric synthesis of a potent inhibitor of 15-prostaglandin dehydrogenase. Enzymatic resolution of alpha-sulfinyl esters gives recovered ester and alpha-sulfinyl acid in high enantiomeric purity. Decarboxylative functionalization provides access to a wide range of optically active sulfoxides in both enantiomeric forms.image