THE USE OF 1,2-SHIFTS IN CARBENES AND NITRENES IN THE GENERATION OF NOVEL HETEROCUMULENES

Ethenedithione, S=C=C=S, has been generated in flash vacuum pyrolysis (FVP) reactions from isoxazolone and Meldrum's acid derivatives and ch aracterized by IR, UV and mass spectrometry. Evidence for the existenc e of HN=C=C=S and its isomerization to thioformyl cyanide is also pres ented. The preparation and characterization of iminopropadienone deriv atives RN=C=C=C=X (X = O, S, or NR') from a variety of isoxazole compo unds is described. These highly reactive cumulenes are formed via viny lidene, vinylnitrene, and ketenimine intermediates.