Ambident lithium carbanions of allyl phenyl sulfones add 1,4-α to both acyclic and cyclic enones exclusively if HMPA is present in the medium; in contrast, 1,2-α addition to cyclic enone is the major kinetic course in the absence of HMPA, which is followed by rearrangement to the 1,4-γ adduct.
如果介质中存在HMPA,则烯丙基苯基砜的环境
锂碳负离子会分别向无环和环状烯酮中添加1,4-α。相反,在不存在HMPA的情况下,向环烯酮中添加1,2-α是主要的动力学过程,然后将其重排为1,4-γ加合物。