Electrosynthesis of homoquinone and oxygenated heterocycles in the reduction of 1,2-Naphthoquinone in the presence of phenacyl bromide M. Belén Batanero Hernán , Laura Pastor, Noemi Salardón, Sara Cembellin Universidad de Alcalá, Spain Cyclopropanes are privileged compound whose enhanced metabolic stability and conformational rigidity over unsubstituted methylene units offer distinct advantages to medicinal chemists [1] . Further, cyclopropanes are structural units of several bioactive natural products and pharmaceutically important compounds including many marketed drugs [2] . A series of new trans- and cis-benzoyl-homoquinones (cyclopropane-fused quinone systems) were stereoselectively prepared [3] in good yield by the electrochemical reduction of 1,4-quinones to the corresponding radical anions -that acted as electrogenerated bases (EGB)- in the presence of α-bromoacetophenones or α-bromo propiophenone in DMF/LiClO4 as SSE. When this reaction is performed with 1,2-naphthoquinone, the nature of products (Figure 1) and their yield depend on the experimental conditions. Rationalized mechanism proposals are suggested and discussed.
References 1. M. Watanabe, T. Kobayashi, T. Hirokawa, A. Yoshida, Y. Ito, S. Yamada, N. Orimoto, Y. Yamasaki, M. Arisawa, S. Shuto, Org. Biomol. Chem. 2012, 10, 736. 2. a) D. Y.-K Chen, R.H. Pouwer, J.-A. Richard, Chem. Soc. Rev. 2012, 41, 4631. b) S. J. Chawner, M.J. Cases-Thomas, J.A. Bull, Eur. J. Org. Chem. 2017, 5015, and references cited therein. 3. K. Hamrouni, F. Barba, M.L. Benkhoud, B. Batanero. Journal of Organic Chemistry, 2017, 82, 6778.
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