An Efficient and Convenient Synthesis of Bridged δ-Lactones
endo-4-Ethoxycarbonyl-4-(phenylthio)-9-methylene-2-oxabicyclononan-3-ones (5a-c) and their related compounds 5e-h, and endo-4-ethoxycarbonyl-4-(phenylthio)-8-methylene-2-oxabicyclooctan-3-one (5d) were synthesized from α-diazomalonates 3 of 2-(phenylthio)cyclohex-2-en-1-ols (1a-c) and their related compounds 1e-h, and 2-(phenylthio)cyclopent-2-en-1-ol (1d), respectively, via the sigmatropic rearrangement of cyclic allylsulfonium ylides 4.