Ring Expansion of Lactones and Lactams via Propiolate 1-Carbon Intercalation
作者:Tina N. Grant、Chantel L. Benson、F. G. West
DOI:10.1021/ol8014682
日期:2008.9.18
available five- and six-membered lactones and N-sulfonyllactams undergo efficient addition of t-butyl propiolate, and the resulting adducts undergo cycloisomerization to six- and seven-membered cyclic ethers or amines in the presence of pyridinium acetate. The ring expansion process occurs in generally good yields and is proposed to involve a nucleophilic catalysis mechanism.