Desulfurization of the δ-sultones 2 with simultaneous formation of an exocyclic olefin is achieved by alkylation of 2 with (iodomethyl)trimethylsilane and subsequent treatment of the resultant products 7 with tetra-n-butylammonium fluoride. Application of this two-step procedure to sultone 8 leads to 1,3-diene 10, an intermediate for the synthesis of the highly oxygenated 1,10-secoeudesmanolides eriolanin and eriolangin.