Direct electrochemical oxidation of abietanes Inês Martins, Jaime A. S. Coelho, Carlos A. M. Afonso University of Lisbon, Portugal
Colophony, a natural resin obtained from coniferous trees, is constituted by a group of diterpenes known as abietanes, which, along with its derivatives, has been found to have a wide variety of interesting biological activities, including the antimicrobial, antiviral, antitumoral, and anti-inflammatory activities. Constituents of this resin have a wide range of industrial applications, including synthetic rubbers, adhesives and fragrances. [1,2] The benzylic oxidation of dehydroabietic acid, an abietane from colophony, and its methyl ester derivative, has been reported using oxidative protocols, such as using Jones reagent [3], Swern oxidation [4] or either using Chromium trioxide in stoichiometric [5] or catalytic quantities. [6] However, these protocols fail in the context of sustainability for several reasons, such as the use of toxic reagents and stoichiometric amounts. The electrochemistry equipment used in this work were an ElectraSyn 2.0 system by IKA. Herein, we report an electrochemical method for the benzylic oxidation of dehydroabietic acid, an alternative greener protocol for the formation of the benzylic ketone in very good yields using modern electrochemical methods. Moreover, this method can be applied to the corresponding methyl ester derivative. [7-9] References 1. M.A. González, et al. Eur J Med Chem. 44(6), 2009, 2468–2472. 2. G. Eksi, et al. Elsevier Inc., 2020, 313–345 p.
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