(1R)-2-[(3R,4S)-3-Methyl-4-(N-phenyl-N-propionylamino)piperidin-1-yl]-1-phenylethyl p-bromobenzoate and N-[(3R,4S)-1-[(2S)-2-(4-bromophenyl)-2-hydroxyethyl]-3-methyl-piperidin-4-yl]-N-phenylacrylamide.

ABSTRACT

Both title compounds, C(30)H(33)BrN(2)O(3) and C(23)H(27)BrN(2)O(2), respectively, are brominated derivatives of the potent opioid cis-beta-hydroxy-3-methylfentanyl (ohmefentanyl). Ohmefentanyl has three asymmetric C atoms and, therefore, has eight possible stereoisomers. The absolute configurations of the title compounds were determined to assign the proper configuration of two of these stereoisomers and the compounds have the same stereochemistry at two of the three asymmetric C atoms.