
%0 Journal Article
%A Besida, J 
%A Brown, RFC 
%A Colmanet, S 
%A Leach, DN 
%T Methyleneketenes and methylenecarbenes. XVII. Generation of methyleneketene intermediates by pyrolysis of N-alkenoylpyrazoles and synthesis of simple phenols
%J Australian Journal of Chemistry
%D 1982/07/01
%V 35
%N 7
%P 1373-1383
%K 
%R https://doi.org/10.1071/CH9821373
%U https://www.publish.csiro.au/paper/CH9821373 
%X Flash vacuum pyrolysis of 1-acyl-3,5-dimethylpyrazoles forms ketenes, but the conditions may lead to decarbonylation of the ketene. The 1-cinnamoyl derivative (4) forms phenylacetylene at 750&#176;/0.02 mm, via benzylideneketene and benzylidenecarbene. Simple phenols (2-naphthol, phenol, 4-methylphenol, 2,4-dimethylphenol, and 3,5-dimethylphenol) are obtained in high yield on pyrolysis of the appropriate dienoylpyrazoles (10), (13), (16), (18) and (21); the reaction proceeds by way of cyclization of dienylketenes. 
