Double α-Addition Reaction of ortho-Hydroxyacetophenones to Ethyl Propiolates Mediated by Ph3P: Synthesis of Functionalized 1,4-Pentadienes - Meng, Ling-Guo; Tang, Kai; Liu, Hui-Fang; Xiao, Jiang; Xue, Song (Synlett, 2010)