A DIRECTED STEREOSELECTIVE ALDOL REACTION - SIMPLE SYNTHESIS OF ENANTIOPURE DELTA-HYDROXY-BETA-ENAMINO KETONES BY CONDENSATION OF HOMOCHIRAL BETA-ENAMINO KETONES WITH ALDEHYDES AND KETONES

Authors
CIMARELLI C PALMIERI G CAMALLI M
Citation
C. Cimarelli et al., A DIRECTED STEREOSELECTIVE ALDOL REACTION - SIMPLE SYNTHESIS OF ENANTIOPURE DELTA-HYDROXY-BETA-ENAMINO KETONES BY CONDENSATION OF HOMOCHIRAL BETA-ENAMINO KETONES WITH ALDEHYDES AND KETONES, Tetrahedron : asymmetry, 7(7), 1996, pp. 2099-2112
Citations number
39
Categorie Soggetti
Chemistry Inorganic & Nuclear","Chemistry Inorganic & Nuclear","Chemistry Physical
Journal title
Tetrahedron : asymmetry → ACNP
ISSN journal
09574166
Volume
7
Issue
7
Year of publication
1996
Pages
2099 - 2112
Database
ISI
SICI code
0957-4166(1996)7:7<2099:ADSAR->2.0.ZU;2-Y
Abstract
A simple synthesis of enantiopure anti-delta-Hydroxy-beta-enamino keto nes 3 by condensation of homochiral lithium dianions derived from beta -enamino ketones 1('') with aldehydes and ketones is reported. The mec hanism for the directed enantioselective aldol reaction was investigat ed. The anti delta-hydroxyenaminone 3 is obtained as the major diaster eomer through an open transition state. In acidic conditions the delta -hydroxyenaminones 3 are cyclized to 4-imino-2,3-dihydropyranones 4 wh ich are instable and isomerize spontaneously to gamma alkylidenenamino nes 5. Copyright (C) 1996 Elsevier Science Ltd