Bifunctionalized allenes, VII: Two methods for one-pot synthesis of sulfonyl-functionalized allenecarboxylates and phosphorylated allenes

Two new approaches to the synthesis of sulfonyl-functionalized allenecarboxylates and phosphorylated allenes are described. 2-Sulfonyl-alka-2,3-dienoates were readily prepared in an one-pot reaction by [2,3]-sigmatropic rearrangement of sulfinato-substituted 2-alkynoates, in situ generated from ethyl propynoate and subsequent treatment with lithium diisopropyl (LDA), ketone, trimethylchlorosilane (TMSCl), and the corresponding sulfinyl chlorides. Preparation of 1-sulfonyl-alka-1,2-dienephosphonates and -1,2-dienyl phosphine oxides consists of the reaction of the lithio compounds, in situ generated from phosphorylated allenes and LDA, with the corresponding sulfonyl chlorides.