Canadian Journal of Chemistry p. 32 - 37 (1996)
Update date:2022-08-05
Topics:
Bender, Christopher Owen
Benzocyclooctatetraene (i.e., COT, 2) is the major product from the thermolysis and direct photolysis of 2,3-benzobicyclo[4.2.0]octa-2,4,7-triene (i.e., triene 1). It is also a minor product from the sensitized irradiation of 1. The mechanism of the reaction 1→2 was investigated using deuterium-labelled triene (i.e., 1a/b), which was prepared in a two-step procedure from a known triene mixture (1a) containing deuterium at both C-4 (43%) and C-5 (97%): the thermolysis of 1a led to labelled COT 2a, which upon direct irradiation (λ ≥ 310 nm) gave the deuterated triene mixture 1a/b in good chemical yield (61%) but in low quantum efficiency (Φ ≈ 0.0001). The COT produced from the direct irradiation (Corex filter) of 1a/b possessed different deuterium distributions than when generated thermally or from triplet sensitization (p-dimethylaminobenzophenone), as determined by 1H NMR integration. The observed deuterium-labelling patterns are in accord with a Zimmerman di-π-methane rearrangement being involved in formation of the COT from S1 of triene 1, while a mechanism proceeding by initial cleavage of the cyclobutene C1-C6 bond appears to operate during the thermal or sensitized (T1) generations of 2.
View MoreNanjing Chemipioneer Pharma&Tech Co.,Ltd
website:http://www.chemipioneer.com.cn
Contact:+86-25-52685700
Address:Room 305,A Block,Biological-Medicine Building,Business Start-up Center,Xin-ke 1st Road, High-tech development zone,Nanjing city,Jiangsu Province, China
Changzhou Ansciep Chemical Co.,Ltd.
Contact:+86 519 8630 5871
Address:A-710 Boan International, 8 East Guangdian Road,Wujin,Changzhou
Zhejiang Linhai Xinhua Chemicals Factory
Contact:0086-13661858911
Address:Xunqiao Development Zone, Linhai, Zhejiang, China
Contact:+86-21-6856-1349 523-87676172
Address:No16 . BinJiang Road . Taixing Economy Developing Area .JiangSu Province . China
Contact:+86-571-86217390
Address:No.567 Dengcai Street,Sandun,Westlake District,Hangzhou310030,Zhejiang,China.
Doi:10.1016/S0040-4039(00)75961-2
(1968)Doi:10.1016/S0960-894X(98)00183-8
(1998)Doi:10.1016/S0960-894X(00)00097-4
(2000)Doi:10.1016/j.steroids.2005.06.007
(2005)Doi:10.1016/S0277-5387(97)00400-2
(1998)Doi:10.1016/S0040-4039(98)00700-X
(1998)