Stereoselective synthesis of chiral polyfunctionalized cyclohexane derivatives. Palladium(II)-mediated reaction between cyclohexenones and diazomethane

Authors
Rodriguez-Garcia, C Ibarzo, J Alvarez-Larena, A Branchadell, V Oliva, A Ortuno, RM
Citation
C. Rodriguez-garcia et al., Stereoselective synthesis of chiral polyfunctionalized cyclohexane derivatives. Palladium(II)-mediated reaction between cyclohexenones and diazomethane, TETRAHEDRON, 57(6), 2001, pp. 1025-1034
Citations number
38
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON
ISSN journal
00404020 → ACNP
Volume
57
Issue
6
Year of publication
2001
Pages
1025 - 1034
Database
ISI
SICI code
0040-4020(20010204)57:6<1025:SSOCPC>2.0.ZU;2-0
Abstract
Several chiral polyfunctionalyzed cyclohexanones and cyclohexenones have be en synthesized through Diels-Alder cycloadditions, stereoselectivity being stated by X-ray structural analysis and NOE experiments. The chemoselectivi ty in the paladium(II)-catalyzed reaction between cyclohexenones and diazom ethane has been investigated. Thus, in those enones bearing an amide functi on on the gamma -carbon, the preferential addition occurs at the carbonyl g iving epoxides which, under acid conditions, rearrange to tetrahydrobenzoxa zoles. The other cyclohexenones afford cyclopropanes as a result of additio n to the C=C bond. A mechanistic approach to explain the whole process is p roposed. (C) 2001 Elsevier Science Ltd. All rights reserved.