
TY  - JOUR
A1  - Besida, J 
A1  - Brown, RFC 
A1  - Colmanet, S 
A1  - Leach, DN 
T1  - Methyleneketenes and methylenecarbenes. XVII. Generation of methyleneketene intermediates by pyrolysis of N-alkenoylpyrazoles and synthesis of simple phenols
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1982
VL  - 35
IS  - 7
SP  - 1373
EP  - 1383
KW  - 
UR  - https://doi.org/10.1071/CH9821373 
N2  - 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. 
ER  -

