The title compound(9S,13R,14S)-7,8-dehydro-4-(4?-bromo-benzyloxy)-3,7-dimethoxy-17-methyl-morphinan-6-one monohydrate(O-4-bromobenzylsinomenine)was synthesized by the reaction of(9S,13R,14S)-7,8-dehydro-4-hydroxy-3,7-dimethoxy-17-methyl-morphinan-6-one with 4-bromobenzyl alcohol.Its chemical structure was determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P21 with a=8.890(2),b= 14.757(4),c=9.205(2)?,β=91.577(4)°,C_(26)H_(30)BrNO_5,Mr=516.42,μ=1.740 mm~(-1),V=1207.2(...