The reaction of sodium alcoholates of sec- or tert- α-acetylenic alcohole having no ethynyl group with carbon disulfide in an aprotic solvent gave 4-alkylidene-1, 3-oxathiolane-2-thiones, but from alcohols having ethynyl group 4-methylidene-1, 3-dithiolane-2-thiones, or their rearranged isomers were mainly isolated, and in the case of 1-hexyn-3-ol (VI) or 1-ethynylcyclohexano 1 (XV) 4-methylidene-1, 3-oxathiolane-2-ones were also isolated.
