The oxidation of thiocarbonates with lead tetra-acetate and with peracids

Abstract

Cyclic trithiocarbonates react rapidly with 1 mol. of lead tetra-acetate, which attacks the thione sulphur atom to form an oxythiocarbonyl compound. Cyclic mono- and di-thiocarbonates of the thione type also consume 1 mol. of the reagent, but in these compounds the thione function is converted into a carbonyl group; an exception is the catechol derivative, 1,2-thiocarbonyldioxybenzene, which gives a disulphide. Cyclic mono- and di-thiocarbonates not of the thione type are unchanged; relative to a trithiocarbonate they are also much less readily attacked by periodate.

Reaction of a cyclic trithiocarbonate with 1 mol. of peracetic acid also gives the oxythiocarbonyl compound, but with an excess of the reagent the products are a disulphonic acid and a methylenedisulphonyl compound; formation of the latter involves the conversion of a thiocarbonyl function into a methylene group.

Mechanisms are suggested for these transformations.