Unexpected stereoselectivity in the anionic oxy-Cope rearrangement of acyclic enol ethers

Citation
Ap. Rutherford et Rc. Hartley, Unexpected stereoselectivity in the anionic oxy-Cope rearrangement of acyclic enol ethers, TETRAHEDR L, 41(5), 2000, pp. 737-741
Citations number
14
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
41
Issue
5
Year of publication
2000
Pages
737 - 741
Database
ISI
SICI code
0040-4039(20000129)41:5<737:USITAO>2.0.ZU;2-P
Abstract
The anionic oxy-Cope rearrangement of alkoxides derived from (1E,SZ)-4-meth yl-5-alkoxy-1-pheny-1,5-heptadien-3-ols proceeds via a chair-like transitio n state with the oxyanion axial, even when there is a 3,4-relationship betw een the methyl group and the oxyanion so that both groups are axial in the transition state of the [3,3]-sigmatropic rearrangement. We believe that th is is the first example of chelation control in the AOC rearrangement. The reaction forms the basis of a stereoselective synthesis of beta-hydroxycycl ohexanones containing four chiral centres. (C) 2000 Elsevier Science Ltd. A ll rights reserved.