What is "dithiin"

n. (context organic compound English) The unsaturated six-membered heterocycle containing four carbon atoms, two sulfur atoms and two double bonds

Dithiin is a class of heterocyclic compounds, with the parent members having the formula (CH)S. Two isomers of this parent are recognized, 1,2- and 1,4-dithiins. These compounds are antiaromatic consisting of 8π e systems, akin to cyclooctatetraene. Vinyldithiin, a common component of garlic, is a misnomer for 3-vinyl-4H-1,2-dithiin, since true 1,3-dithiins are unknown.