New xanthate-based radical cyclization onto alkynes.

To bypass the failure of radical cyclization involving a xanthate transfer on alkynes, a new reductive cyclization strategy has been completed with the use of a stoichiometric amount of dilauroyl peroxide in isopropanol. When the starting xanthates are prepared via a Ugi 4-component reaction with propargylamine, exomethylene lactams are formed in good yields.