O-Benzoyl­naltrexone

In the title compound, C₂₇H₂₇NO₅ (systematic name: 17-cyclopropylmethyl-14-hydroxy-6-oxo-4,5-epoxymorphin­an-6-yl benzoate), which is the benzoate ester of the opioid receptor antagonist naltrexone, the dihedral angle between the two phenyl rings is 77.1 (1)°. In the crystal, a weak aromatic C—H...O_carbox­yl hydrogen bond involving the benzoate groups of adjacent mol­ecules gives rise to a chain extending along the a-axis direction. The known absolute configuration for the mol­ecule was inferred from a previous naltrexone structure.