Synthesis of difluorodithiopyruvic acid derivatives

The reaction of cadmium sulfide with 1,1-dichloro-3,3-difluoro-2-oxo-1-propylthiopropane yields difluorodithiopyruvic propionate. This reacts with morpholine to give difluorodithiopyruvic morpholide; it also undergoes a cycloaddition reaction to the carbon–sulfur double bond with dimethylbutadiene to form 2-difluoroacetyl-4,5-dimethyl-2-propylthio-3H,6H-thiopyran.