Highly diastereoselective aldol reactions with camphor-based acetate enolate equivalents

Citation
C. Palomo et al., Highly diastereoselective aldol reactions with camphor-based acetate enolate equivalents, J ORG CHEM, 64(22), 1999, pp. 8193-8200
Citations number
100
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
JOURNAL OF ORGANIC CHEMISTRY
ISSN journal
00223263 → ACNP
Volume
64
Issue
22
Year of publication
1999
Pages
8193 - 8200
Database
ISI
SICI code
0022-3263(19991029)64:22<8193:HDARWC>2.0.ZU;2-#
Abstract
New lithium enolates of alpha-hydroxy ketones, derived from camphor, are ev aluated for asymmetric aldol reactions in the presence of lithium chloride. The diastereoselectivity of the reactions between the lithium enolate of 3 and a variety of achiral aldehydes is strongly influenced by the lithium c hloride salt. In these instances, the achieved levels of asymmetric inducti on, typically 95:5 dr, are in the range of those attained in aldol reaction s involving the lithium enolate of the methyl ketone 4, which is sterically more demanding. The resulting aldol adducts are easily transformed into be ta-hydroxy carboxylic acids, ketones, and aldehydes with concomitant recove ry of the camphor, the chiral controller of the process, which can be reuse d.