Synthesis of Thiolanes from (E)‐4‐Mercapto‐2‐butenoates via, Consecutive Michael Additions

Abstract Methyl 4‐mercaptocrotonate (4) adds to α,β‐unsaturated nitriles or carbonyl compounds in the presence of Triton B, as base. Several of the primary adducts (10) cyclize to thiolanes (11) in a second (base‐catalysed) Michael addition. Dimerization of 4 under these conditions affords a mixture of the diastereomeric 14‐dithianies 7 and 8.