Synthesis 2003(12): 1797-1802
DOI: 10.1055/s-2003-41035
PAPER
© Georg ThiemeVerlag Stuttgart · New York

Stereoselective Preparationof Functionalized Unsaturated Lactones and Esters via FunctionalizedMagnesium Carbenoids

Viet Anh Vua, Ilan Marekb, Paul Knochel*a
a Department Chemie, Ludwig-Maximilians-UniversitätMünchen, Butenandtstrasse 5-13, 81377 München,Germany
Fax: +49(89)218077680 ; e-Mail: paul.knochel@cup.uni-muenchen.de;
b Department of Chemistry, Technion-IsraelInstitute of Technology, Technion City, Haifa 32000,Israel
Fax: +972(4)8295703; e-Mail: chilanm@techunix.technion.ac.il;
Further Information

Publication History

Received 3 June 2003
Publication Date:
13 August 2003 (online)

Abstract

The reaction of β,β-dibromo or diiodo unsaturatedesters with i-PrMgCl (1 equivalent) indiethyl ether allows the generation of functionalized alkenylmagnesiumcarbenoids which react with retention of configuration with variouselectrophiles providing polyfunctionalized unsaturated esters andlactones. By using two equivalents of i-PrMgCl,a 1,2-migration with retention of configuration occurs in diethylether allowing a new synthesis of tetrasubstituted esters and lactones.