Synthesis 2002(3): 0427-0437
DOI: 10.1055/s-2002-20028
FEATUREARTICLE
© Georg Thieme Verlag Stuttgart · New York

Asymmetric Photodeconjugation: Highly Stereoselective Synthesis of α-Fluorocarboxylic Derivatives

Frédéric Bargiggia, Sylvia Dos Santos, Olivier Piva*
Laboratoire de Chimie Organique - Photochimie et Synthèse - UMR 5622 CNRS, Université Claude Bernard-Lyon I, 43, Bd du 11 novembre 1918, 69622 Villeurbanne, France
Fax: +33(4)72448136; e-Mail: piva@univ-lyon1.fr;
Further Information

Publication History

Received 23 November 2001
Publication Date:
28 July 2004 (online)

Abstract

Irradiations of α-fluoro-α,β-unsaturated esters lead to the corresponding α-fluoro-β,γ-unsaturated isomers in good yields. The reaction required the use of an achiral base (typically an amine) to promote the protonation of the photodienolic intermediate. By replacing the ethyl group with a diacetone-d-glucose moiety, the reaction can be carried out in a diastereoselective manner to furnish the deconjugated esters with similar yields and selectivities up to 95%. The adducts were submitted to osmylation conditions to deliver α-fluoro-β-hydroxy-butyrolactones in one single step.