γ-heterosubstituted γ-methyl-α,β-butenolides are presented, starting mainly from C3 synthons (glyceraldehyde, glycidaldehyde, acrolein and 2,3-epoxypropyl ethers). Good general methods for the preparation of γ-hydroxymethyl-α,β-butenolide 2, several of its ether derivatives, as well as of γ-bromomethyl-α,β-butenolide 5, are given. The reactivities of these structurallysimple but highly functionalized compounds
Studies on structurally simple αβ-butenolides. IV. behaviour of protoanemonin as electrophile towards alcohols and thiols
作者:A. Calderon、J. Font、R.M. Ortun¯o
DOI:10.1016/s0040-4020(01)88808-6
日期:1984.1
Protoanemonin, reacts in different ways with thiolate and alkoxide anions. Thus, while the very soft nucleophile benzenethiolate attacks exclusively the olefinic carbons of 1, alkoxides always attack the carbonyl group in the first step of the reaction. In intermediate cases, when neither very hard nor very soft nucleophiles are used, regioselectivity is not observed. Mechanisms are discussed to explain