Tellurium-triggered mild, base-free generation of enolates from acylcyclopropanemethanol tosylates and their trapping by electrophiles

ORGN 594

Donald C. Dittmer, Dmytro Avilov, Mahesh G. Malusare, and Engin Arslancan. Department of Chemistry, Syracuse University, Room 1-014, CST, Syracuse, NY 13244
Homoallylic lithium enolates from acylcyclopropanemethanol tosylates or mesylates and lithium telluride are generated cleanly under mild, base-free conditions and can be trapped in reactions with electrophiles such as trimethylsilyl chloride, aldehydes, ketones, or alkyl halides. The aldol reaction of the tert-butyl-substituted enolate with benzaldehyde at –78 oC affords the syn-aldol product with high diastereoselectivity (ratio syn/anti 17:1). At higher temperatures and a longer reaction time the more thermodynamically stable anti-aldol product is formed, also with high diastereoselectivity (ratio syn/anti 1:25). A spirocyclopentadienyl derivative underwent ring opening to give a 57:43 mixture of 2- and 1-allylcyclopentadienes.

 

New Reactions, Methodology, Heterocycles, Aromatics
8:00 PM-10:00 PM, Wednesday, August 25, 2004 Pennsylvania Convention Center -- Hall D, Poster

Division of Organic Chemistry

The 228th ACS National Meeting, in Philadelphia, PA, August 22-26, 2004