Oxidative Nitration and Bromination of Berbin-8-one
摘要:
In presence of two equivalents of nitric acid berbin-8-one (1) could be oxidized and nitrated to give 13-nitro-13,13a-dehydroberbin-8-one (2) in good yield. In the same way berbin-8-one (1) was made to react with N-bromosuccinimide to afford the 13-bromo analogue (3). The mechanism of the nitrative oxidation was studied. This oxidation is initiated by nitrogen dioxide from nitrous fumes included in the nitric acid. The oxidative nitration is accelerated by increasing the acidity or temperature of the medium. A radical mechanism which involves the 13,13a-dehydro-berbin-8-one (9) as intermediate of the reaction is postulated and discussed. The potential of this synthetic route was investigated.
Oxidative Nitration and Bromination of Berbin-8-one
摘要:
In presence of two equivalents of nitric acid berbin-8-one (1) could be oxidized and nitrated to give 13-nitro-13,13a-dehydroberbin-8-one (2) in good yield. In the same way berbin-8-one (1) was made to react with N-bromosuccinimide to afford the 13-bromo analogue (3). The mechanism of the nitrative oxidation was studied. This oxidation is initiated by nitrogen dioxide from nitrous fumes included in the nitric acid. The oxidative nitration is accelerated by increasing the acidity or temperature of the medium. A radical mechanism which involves the 13,13a-dehydro-berbin-8-one (9) as intermediate of the reaction is postulated and discussed. The potential of this synthetic route was investigated.