A thiyl radical mediated cascade sequence for the co-cyclisation of 1,6-hexadienes with sulfur atom transfer

The paper describes a method for effecting the co-cyclisation of 1,6-dienes with concomitant sulfur atom transfer. The key step is a cascade reaction involving the addition of a thiyl radical to an alkene, cyclisation through a chair-like transition state and termination by homolytic substitution at sulfur. It has been used to synthesise a broad range of fused thiabicyclo[3.3.0]octanes.