A New Synthesis and the ¹³C-NMR OF β-Cyperone 1,3-Dibromo-2-Pentene, A New Ethyl Vinyl Ketone Equivalent

Abstract

In connection with another study underway i n this lab we have been investigating the use of vinylogous thioester 1 as a synthon f o r sesquiterpene synthesis. We have found that 1 is useful for ring annelations and introduction of multiple substituents when pursuing carbocyclic synthesis. In recent studies with thioesters we have found that the lithium enolate of 1 (LDA/THF) will undergo 1,4-addition to Michael acceptors such as ethyl vinyl ketone (2, - EVK) in moderate yields (∼60).