A new method for synthesis of five-membered carbocycles: use of the ester enolate rearrangement in conjunction with radical cyclization

Abstract

4-(Phenylseleno)butyryl esters (2), easily prepared from allylic alcohols, are convertible into cyclopentanes by successive ester enolate rearrangement (2)→(3) and 5-exo-trigonal radical cyclization (4)→(6); this general process is efficient and the stereochemical result is predictable.