An unusual and highly efficient access to thieno[2,3-b]-benzothiopyran structures

Article abstract of DOI:10.1016/S0040-4039(99)00285-3

Dihydrothieno[2,3-b]-benzothiopyran-4-ones are easily obtained by an intermolecular radical addition to an unactivated olefin using an S-o- fluorophenacyl xanthate followed by a novel, base induced domino cyclisation.