Sonawane, H. R.; Sethi, S. C.; Merchant, S. N., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1984, vol. 23, # 10, p. 934 - 939
Functionalization of Benzonorbornadiene: High-Temperature Bromination and Electrochemical Oxidation
摘要:
The electrophilic addition of bromine to benzonorbornadiene (1) at 10 degrees C led in high yield to the formation of 2-exo-7-anti-dibromide 2. However, high-temperature bromination in decalin at 150 degrees C resulted in the formation of five products, 2-6, consisting of non-rearranged and rearranged products in a ratio of 8:2. Conducting the bromination reaction in the presence of a free radical inhibitor like 2,4,6-tri-tert-butylphenol suppressed the formation of the non-rearranged products. This very strongly supports the assumption that there is a competition between radical and ionic reactions. Anodic oxidation of benzonorbornadiene was investigated. Electrolysis of benzonorbornadiene in different solvents resulted in the formation of 2,7-disubstituted benzonorborn-5-ene derivatives, 8-11, in good yields.