M. Calmes et al., TERTIARY-AMINES - A DECISIVE FACTOR IN THE STEREOSELECTIVE ADDITION OF (R)-PANTOLACTONE TO N-PHTHALYL VALINE KETENE, Tetrahedron, 53(40), 1997, pp. 13719-13726
The stereoselective base-catalyzed addition of (R)-pantolactone to the
ketene derived from racemic N-phthalyl valine is reported. The R or S
configuration of the newly generated asymmetric centre of the pantola
ctonyl ester is highly dependent on the tertiary amine catalyst employ
ed. (C) 1997 Elsevier Science Ltd.