Efficient synthesis of 5-substituted thiazolidin-2-ones from xanthates and tert-butyl N-allylcarbamates

A series of 5-substituted thiazolidin-2-ones with various functional groups was synthesized efficiently via a radical addition of xanthates and tert-butyl N-allylcarbamates and subsequent 88% HCO2H-catalyzed cyclization. The mechanism of the acid-catalyzed cyclization was proposed as well.