FLASH VACUUM PYROLYSIS OF STABILIZED PHOSPHORUS YLIDES - PART 12 - EXTRUSION OF PH3P FROM SULFONYL YLIDES AND REACTIVITY OF THE RESULTING SULFONYL CARBENES

Twelve sulfonyl stabilised phosphorus ylides have been prepared and th eir behaviour upon flash vacuum pyrolysis at 600 degrees C has been ex amined. Examples with an arylsulfonyl substituent undergo loss of Ph3P O to give intractable products but those with an arylmethylsulfonyl su bstituent separately lose Ph3P and SO2 to give products consistent wit h the intermediacy of sulfonyl carbenes. X-Ray structure determination s of one ylide from each series show a more significant P-O non-bondin g interaction in the first case, providing some explanation for the di fferent thermal reactivity.