Bromination of 17-O-acetyltestosterone (17b b-acetoxyandrost-4-en-3-one) (1) was performed with 1, 5, and 10 eq of Br 2 in AcOH-Et 2 O at room temperature. In all cases 2a a,6b b-(2) and 2a a,6a a-dibromo-17b b-acetoxyandrost-4-en-3-one (3) were obtained, although the yields were dependent upon the conditions used. Bromination of compound 1 with 10 eq of Br 2 in the presence of silver trifluoromethanesulfonate (silver triflate, AgOTf) at room temperature for 12 h gave 2,7a a-dibromo-(4) and 2,4,7a a-tribromo-17b b-acetoxy-3-hydroxy-1-methylestra-1,3,5(10)-triene-6-one (5). The formations of the products were inferred on the basis of products obtained under controlled brominations of 1 in the presence of AgOTf, and of those obtained by the brominations of compounds 9-13 also in the presence of AgOTf.