Synthesis and Structure of a Dispirocyclic 1,3-Dithiolane-S-oxide

Mloston, Grzegorz; Heimgartner, Heinz (1995). Synthesis and Structure of a Dispirocyclic 1,3-Dithiolane-S-oxide. Polish Journal of Chemistry, 69:1649-1654.

Abstract

The reaction of a 2,5-dihydro-1,3,4-thiadiazole and a sulfine in THF at 50°C yields a 1,3-dithiolane-S-oxide as the major product. The formation of the latter is rationalized by the 1,3-dipolar cycloaddition of a thiocarbonyl-S-ylide, generated by thermal N2-elimination from the corresponding 2,5-dihydro-1,3,4-thiadiazole, onto the sulfine (C=S)-bond. The structure of the dispirocyclic 1,3-dithiolane-S-oxide has been established by X-ray crystallography.

Abstract

The reaction of a 2,5-dihydro-1,3,4-thiadiazole and a sulfine in THF at 50°C yields a 1,3-dithiolane-S-oxide as the major product. The formation of the latter is rationalized by the 1,3-dipolar cycloaddition of a thiocarbonyl-S-ylide, generated by thermal N2-elimination from the corresponding 2,5-dihydro-1,3,4-thiadiazole, onto the sulfine (C=S)-bond. The structure of the dispirocyclic 1,3-dithiolane-S-oxide has been established by X-ray crystallography.