ASYMMETRIC-SYNTHESIS OF KETOPROFEN - A SURPRISING BASE CATALYST EFFECT DURING ASYMMETRIC ADDITION OF PANTOLACTONE TO METHYL (3-BENZOYLPHENYL) KETENE

Authors
CALMES M DAUNIS J JACQUIER R NATT F
Citation
M. Calmes et al., ASYMMETRIC-SYNTHESIS OF KETOPROFEN - A SURPRISING BASE CATALYST EFFECT DURING ASYMMETRIC ADDITION OF PANTOLACTONE TO METHYL (3-BENZOYLPHENYL) KETENE, Tetrahedron, 50(23), 1994, pp. 6875-6880
Citations number
33
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
50
Issue
23
Year of publication
1994
Pages
6875 - 6880
Database
ISI
SICI code
0040-4020(1994)50:23<6875:AOK-AS>2.0.ZU;2-H
Abstract
The best diastereoselectivity of addition of a chiral alcohol to the k etene derived from ketoprofen was obtained with R or S pantolactone (e d=99%). Depending on the tertiary amine used both for ketene formation and as catalyst during addition, the diastereoisomeric ratio of ester s could be strongly modified and even inverted. Mild saponification af forded R or S ketoprofen in enantiomeric excess of up to 99%.