Stereoselective Synthesis of Highly Substituted Cyclopentenones through [4+1] Annulations of Trialkylsilyl Vinyl Ketenes with alpha-Benzotriazolyl Organolithium Compounds

摘要

Cyclopentenones serve as valuable synthetic building blocks nd are themselves key features in the structure of a number of prostaglandins and other bioactive natural products. Popular strategies for the construction of this important ring system include the intramolecular aldol reaction,the Nazarov cvclization,the Rautenstrauch rearrangement,and the Pauson-Khand reaction.Only a few general [4+1] routes to five-membered carbocycles have been reported to date,one example being the method we developed based on anion-accelerated vinylcyclopropane rearrangements.