Influence of a substituent at C3 on the direction of bromination of estra-1,3,5(10)trien-17-ones

The influence of a C₃ substituent on the direction of bromination of estra-1,3,5 (10)-trien-17-one is discussed: Estrone and its methyl ether give mainly derivatives bromine-substituted in ring A, while the bromination of estrone acetate leads to the production of 16-mono- and 16,16,dibromo-substituted estrones.A. Ordzhonikidze All-Union Scientific-Research Institute of Pharmaceutical Chemistry, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 327–330, May–June, 1984.