(S)-ETHYL 4,4-DIMETHYL PYROGLUTAMATE AS A NEW QUAT CHIRAL AUXILIARY IN ALDOL CONDENSATIONS

Authors
EZQUERRA J RUBIO A MARTIN J NAVIO JLG
Citation
J. Ezquerra et al., (S)-ETHYL 4,4-DIMETHYL PYROGLUTAMATE AS A NEW QUAT CHIRAL AUXILIARY IN ALDOL CONDENSATIONS, Tetrahedron : asymmetry, 8(5), 1997, pp. 669-671
Citations number
11
Categorie Soggetti
Chemistry Inorganic & Nuclear","Chemistry Inorganic & Nuclear","Chemistry Physical
Journal title
Tetrahedron : asymmetry → ACNP
ISSN journal
09574166
Volume
8
Issue
5
Year of publication
1997
Pages
669 - 671
Database
ISI
SICI code
0957-4166(1997)8:5<669:(4PAAN>2.0.ZU;2-R
Abstract
Enolates I, derived from the N-propionyl derivative of the 'quat' chir al auxiliary (S)-ethyl 4,4-dimethyl pyroglutamate 4 undergo highly ste reoselective aldol reactions, which upon hydrolysis and removal of the chiral auxiliary yields the (2R,3R)-3-hydroxy-2-methylpropionic acid 9 in homochiral form. Remarkably, the stereogenic center of 4 was not affected during all the chemical transformations and it could be regen erated after the process in 70% yield. (C) 1997 Elsevier Science Ltd.