Dimethyl trithiocarbonate (4), which was formed as one of by-products in the preparation of α-acetylenyl xanthate (3), was obtained by treating 2-propynyl xanthate (10) or 3-phenyl-2-propynyl xanthate (18) with potassium xanthate (17). The reaction pathway for the formation of 4 from 18 was studied in detail, and the mechanism of the formation of dimethyl trithiocarbonate (4) and other by-products were consequently clarified.
