An efficient synthesis of ( E)-α,β-unsaturated ketones and esters with total stereoselectivity by using chromium dichloride

Abstract

( E)-α,β-Unsaturated ketones 1 or esters 2 can be obtained with complete stereoselectivity by reaction of different 2-chloro-3-hydroxy ketones 3 or esters 4 and CrCl 2. A comparative study of the results of synthesis of ketones 1 with CrCl 2 or samarium is performed. A mechanism to explain both β-elimination reactions has been proposed.