Journal of the Chemical Society. Perkin transactions II p. 365 - 370 (1987)
Update date:2022-08-17
Topics:
Chickos, James S.
Frey, H. Monty
The kinetics of thermolysis of 2,2-dimethyl-1-vinylcyclobutane have been investigated as a function of temperature from 263 to 301 deg C.Primary products produced in the reaction include isobutene and butadiene, 4,4-dimethylcyclohexene, 2-methylhepta-1,6-diene, and cis-2-methylhepta-1,5-diene. trans-2-Methylhepta-1,5-diene and 2,4-dimethylhexa-1,5-diene are produced from cis-2-methylhepta-1,5-diene by way of a 3,3-sigmatropic rearrangement.The reaction obeys first-order kinetics and is unaffected by surface.Activation energies (kcal mol-1) and (logA/s-1) for the overall decomposition and for formation of the primary products are 45.73 +/- 0.3 (14.427 +/- 0.12), 47.71 +/- 0.7 (15.087 +/- 0.3), 44.35 +/- 1.6 (12.53 +/- 0.6), 45.0 +/-1.3 (12.24 +/- 0.5), and 38.38 +/- 1.7 (10.785 +/- 0.7), respectively.The regiochemistry observed in fragmentation and in the 1,3-sigmatropic rearrangement of the starting material is discussed in terms of substituent effects found in other cyclobutane and vinylcyclobutane thermolyses.The fragmentation process and the isomerization to 4,4-dimethylcyclohexene and 2-methylhepta-1,6-diene is believed to proceed through the intervention of 6-methylhept-1-ene-3,6-diyl. cis-2-Methylhepta-1,5-diene is formed from a concerted 1,5-sigmatropic rearrangement of the starting material.The factors which affect the stereochemistry of the 1,5-hydrogen shift are discussed.
View MoreXiamen Hisunny Chemical Co.,Ltd
website:http://www.hisunnychem.com
Contact:+86-592-3327115
Address:Unit 603,No.879,Xiahe Road,Meixin Building,Xiamen,China
Fujian Wanke Pharmaceutical Co., LTD.
Contact:+86-598-5026002
Address:Economic development zone,jiangle county
Contact:+86 755 26588093
Address:No.9 Linkong West Street, Hengdian Street, Huangpi District, Wuhan City, China.
Allright GC (Jinan) Biotechnology Ltd.
website:https://www.argcbiotech.com/
Contact:86-18405413579-
Address: No.27566 of Jingshiroad, Huaiyin District, Jinan City(250011), Shandong Province, China.
zhuzhou zhongle chemical co. ltd.
Contact:+86-0731 28228409
Address:Zhuzhou, Hunan, China
Doi:10.1016/S0040-4039(00)90996-1
(1967)Doi:10.1007/BF00928996
()Doi:10.1021/jm00254a017
(1974)Doi:10.1021/op7000996
(2007)Doi:10.1039/c9ob00540d
(2019)Doi:10.1021/ja01091a046
(1965)
