Synthesis 2005(12): 2046-2054  
DOI: 10.1055/s-2005-870027
SPECIALTOPIC
© Georg Thieme Verlag Stuttgart · New York

Diastereoselective Intramolecular Ester Transfer Reaction of N-Alkenylcar­bamate Derivatives Mediated by Zirconocene-Butene Complex: Preparation of α,γ-Disubstituted γ-Aminobutyric Acid (GABA) Derivatives and 2,4-Di­substituted Pyrrolidine Derivatives

Yasushi Takigawaa, Hisanaka Itob, Katsunori Omoderaa, Minoru Kouraa, Yasuyuki Kaia, Emi Yoshidaa, Takeo Taguchi*a
a School of Pharmacy, , Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Fax: +81(426)763257; e-Mail: taguchi@ps.toyaku.ac.jp;
b School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Further Information

Publication History

Received 14 February 2005
Publication Date:
14 July 2005 (online)

Abstract

Zirconium-mediated diastereoselective alkene-carbonyl coupling reactions of N-alkenylcarbamate derivatives are reported. The present alkene-carbonyl coupling reactions using chiral tert-butyl­ 3-butenylcarbamates having a substituent at the homoallylic position proceeded in a highly diastereoselective manner to give α-methyl-γ-substituted γ-aminobutyric acid (GABA) derivatives. Iodination of the intermediary zirconium species gave the α-iodo­methylated γ-aminobutyrates, which were, in turn, converted to the 5-substituted pyrrolidine-3-carboxylate having cis stereochemistry.