ChemInform Abstract: Highly Diastereoselective Esterification of Ketenes Generated in situ from Acyl Chlorides with (R)‐Pantolactone Derivatives.

Abstract

Highly Diastereoselective Esterification of Ketenes Generated in situ from Acyl Chlorides with (R)-Pantolactone Derivatives. -The use of NEt 3 is found to be important to achieve high diastereoselectivity in this reaction. Furthermore, it is discovered that the lactam (IIb) with stronger proton affinity than the title lactone (IIa) is a better chiral auxiliary and provides α-arylpropionic acids with excellent optical purity. -(YAMAGAMI*, T.; HATSUDA, M.; UTSUGI, M.; KOBAYASHI, R.; MORITANI, Y.; Eur.