Acylations of Thiol Ester Enolate Anions

Article abstract of DOI:10.1021/jo01302a006

The synthetic utility of thiol ester anions has been explored.Claisen condensations of thiol esters with isopropylmagnesium bromide base proceed in good yield.The Dieckmann reaction of diethyl thiolpimelate to form a six-membered ring proceeds in 74 percent yield, but the corresponding reaction of diethyl thioladipate to provide a five-membered ring gives only 26 percent yield.Neither alkylation of ethyl thiolacetate nor a Michael-type adduct with methyl vinyl ketone could be achieved.The mechanism of the Claisen condensation as it applies to thiol esters is discussed.