The thermal isomerization of 1,1-dimethyl-2-vinylcyclopropane to cis-2-methylhexa-1,4-diene via 1,5-hydrogen migration

✍ Scribed by H. M. Frey; R. K. Solly

• Publisher: John Wiley and Sons
• Year: 1969
• Tongue: English
• Weight: 234 KB
• Volume: 1
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550010506

✦ Synopsis

The gas phase isomerization of 1,l -dimethyl-2-vinylcyclopropane to cis-2-methylhexa-1,4-diene has been studied in a static system. The isomerization is homogeneous and kinetically first order. The rate constants were independent of initial reactant pressure in the range 0.6 to 2 torr and of added nitrogen up to 180 torr. Rate constants determined a t 10 temperatures in the range 200 to 254°C fitted the Arrhenius equation k = 1011.41*0.02 exp (-33,540 i 47 cal/RT) sec-I T h e low A factor and activation energy are consistent with a concerted 1,5-hydrogen migration via a "tight" cyclic transition complex.