Thiaprostanoids 13 were prepared by conjugate addition of mercaptane 6 to cyclopentenones 12 and 20. Novel rearrangements of these compounds to 14 and 15 were interpreted as enolate induced [1, 5]-sigmatropic shift on the corresponding dehydration products 16. Preparation of the various substrates and structural elucidation of new products are described.
