Three-Component and Nonclassical Reaction of Phosphines with Enynes and Aldehydes: Formation of γ-Lactones Featuring α-Phosphorus Ylides

Inverted carbenoid species, generated from attack of phosphines at the α(δ′)-carbon of hex-2-en-4-ynedioic acid dialkyl esters, react with aldehydes to give γ-lactones possessing an α-phosphorus ylide moiety.