Enantioselective [2,3]-Wittig Rearrangement via Sparteine-Mediated Lateral Metalation of N,N-Dialkyl-o-allyloxymethylbenzamides and o-Substituted Benzyl Prenyl Ethers

Takeshi Kawasaki; Tetsutaro Kimachi

doi:10.1055/s-1998-1978

Synlett 1998; 1998(12): 1429-1431
DOI: 10.1055/s-1998-1978

letter

© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Enantioselective [2,3]-Wittig Rearrangement via Sparteine-Mediated Lateral Metalation of N,N-Dialkyl-o-allyloxymethylbenzamides and o-Substituted Benzyl Prenyl Ethers

Takeshi Kawasaki^* , Tetsutaro Kimachi

^*Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8304, Japan; Fax + 81 75 761 2689; E-mail: tkimachi@pharmsun.pharm.kyoto-u.ac.jp

Abstract

PDF Download All articles of this category

The (-)-sparteine-mediated enantioselective [2,3]-Wittig rearrangement of N,N-dialkyl-o-allyloxymethylbenzamides and o-substituted benzyl prenyl ethers has been investigated. With N,N-diethyl-o-allyloxymethylbenzamide, enantiomeric excess up to 60% was observed in pentane. These results suggest that the carbamoyl group can effectively assist the transfer of stereoinformation by coordinating with the (-)-sparteine-n-BuLi complex. Other functional groups (OMe, OCONR₂, OMOM, F) were impotent to the enantiodifferentiation of this rearrangement.

[2,3]-Wittig rearrangement - (-)-sparteine - benzyl prenyl ether - lateral metalation

PDF (64 kb)