6141-55-5Relevant articles and documents
Rationale for Predominance of 1,3-Dipolar Cycloreversion in Thermolysis of 3,4-Dihydropyrazole from Ethano-bridged Diphenyldiazomethane and 2,5-Dimethyl-1,4-benzoquinone. An X-Ray Study
Oshima, Takumi,Kawamoto, Tatsuya,Kuma, Hiro,Kushi, Yoshihiko,Nagai, Toshikazu
, p. 1937 - 1938 (1995)
The X-ray crystal structure of the title dihydropyrazole indicates that the steric and ?-conjugative effects associated with the conformational locking of the two phenyl rings are the crucial factors in the predominance of 1,3-dipolar cycloreversion rather than nitrogen extrusion to give the cyclopropane derivative.