title: (3R,4R,4aS,7aR,12bS)-3-Cyclo-propyl-methyl-4a,9-dihy-droxy-3-methyl-7-oxo-2,3,4,4a,5,6,7,7a-octa-hydro-1H-4,12-methano-benzofuro[3,2-e]isoquinolin-3-ium bromide.
abstract: The title compound, C(21)H(26)NO(4) (+)·Br(-), also known as R-methyl-naltrexone (MNTX) bromide, is a selective peripher-ally acting μ-opioid receptor antagonist with a oroxymorphone skeleton, synthesized by hydroxyl protection, N-methyl-ation, deprotection and anion exchange of naltrexone. It comprises a five-ring system A/B/C/D/E. Rings C and E adopt distorted chair conformations, whereas ring D is in half-chair conformation. The C/E ring junctions are trans fused. The dihedral angle between rings D and E is 82.3 (1)°, while the dihedral angles between the planes of rings C and A, and rings D and E are respectively 81.7 (1), 75.9 (1) and 12.2 (1)°. In the crystal, mol-ecules are linked by O-H⋯Br hydrogen bonds.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Chen
authors.forename: Zaiwei
authors.initials: Z
authors.lastname: Zong
authors.forename: Youguo
authors.initials: Y
authors.lastname: Du
authors.forename: Jianguo
authors.initials: J
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Sun