STEREOSELECTIVE CONJUGATE ADDITION OF PROPIONATE TI ATE ENOLATE TO UNSATURATED CHIRAL KETONES - A NEW INSIGHT IN THE REACTION-MECHANISM

Authors
BERNARDI A MARCHIONNI C PILATI T SCOLASTICO C
Citation
A. Bernardi et al., STEREOSELECTIVE CONJUGATE ADDITION OF PROPIONATE TI ATE ENOLATE TO UNSATURATED CHIRAL KETONES - A NEW INSIGHT IN THE REACTION-MECHANISM, Tetrahedron letters, 35(34), 1994, pp. 6357-6360
Citations number
17
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron letters → ACNP
ISSN journal
00404039
Volume
35
Issue
34
Year of publication
1994
Pages
6357 - 6360
Database
ISI
SICI code
0040-4039(1994)35:34<6357:SCAOPT>2.0.ZU;2-K
Abstract
The reactions of the Ti ate enolate 1 and the Li enolate 2 with the ch iral enone 3 were studied. Both reactions are moderately stereoselecti ve, leading to the synthesis of the 2,3-anti-3,4-anti and the 2,3syn-3 ,4anti isomers with 78% and 82% selectivity, respectively. The additio n of 1 appears to take place via an inverse demand Diels-Alder reactio n, rather than a conjugate addition. This finding can explain the diff erent stereochemical behavior of lithium and titanium enolates in the addition to enones.