ChemInform Abstract: First Isolation of Monocyclic Thiabenzenes.

ChemInform Abstract

The unstable thioaldehydes (II), generated in situ from the Bunte salts (I), react with the butadienes (III) to give the dihydrothiopyrans (IV). These are oxidized, forming stereoisomeric mixtures of the sulfoxides (V). Dehydration produces the 6H-thiopyrans (VI) which are S-alkylated to give the thiopyrylium salts (VIII). Deprotonation yields the thiabenzenes (IX) which behave as mesomeric ylides. Further examples as well as rearrangement reactions of (IX) are given in the original paper.