On the reduction of S-alkyl-thionocarbonates (xanthates) with phosphorus compounds.

[reaction: see text] Reductive cleavage of the carbon-sulfur bond present in S-alkyl-thionocarbonates (xanthates) was achieved by high-yielding, tin-free radical reactions based on phosphorus reagents. The combination hypophosphorous acid/triethylamine/AIBN led to fast, efficient, and smooth formation of the alkane. Reduction with diethyl phosphite was sufficiently slow to permit sequential intermolecular addition of a 2-oxoalkyl xanthate onto an olefin followed by cleavage of the newly formed carbon-sulfur bond.