Formation of cyclic sulfonium salts by Me3SiI-promoted intramolecular displacement of hydroxide or methoxide by sulfide. Ring contraction thiepane → thiolane

Article abstract of DOI:10.1016/0040-4020(96)00229-3

A suitably positioned (1,2-, 1,4-, and 1,5-) intramolecular sulfide interferes with the iodotrimethylsilane-promoted iodine for hydroxyl substitution, as well as the related alcohol deprotection procedure (regioselective cleavage of methyl ethers). The ou