THE ADDITION OF THIOLS TO PHOSPHONODITHIOFORMATES - REACTIVITY OF PHOSPHORYLATED DITHIOACETAL DISULFIDES

A high-yielding, thiophilic attack of thiolate ions onto phosphonodithioformates 1 led to the formation of the novel phosphorylated dithioacetal disulfides 2. Their lithiated carbanions could be both alkylated, giving access to [tris(alkylthio)methyl]phosphonates 5 via a [1,2]-Steven's type rearrangement of an intermediate sulfonium ylide D and used in Wittig-Horner reactions to give the ketene dithioacetal disulfides 7, which in turn could be cleaved by thiolate anions to the dithioesters 6. This second sequence represents a new synthesis of dithioesters starting from aldehydes with a one-carbon homologation.