16α-Bromo-17β-hydroxy-5α-androstan-3β-yl acetate

Abstract

The title compound, C21H33BrO3, an intermediate in the synthesis of the neuromuscular blocking agent rocuronium bromide, contains two independent molecules in the asymmetric unit, which have almost identical geometries: in both molecules, the steroidal rings A, B and C have slightly flattened chair conformations and ring D assumes a half-chair conformation. In the crystal, O—H...O hydrogen bonds and weak C—H...O and C—H...Br interactions help to establish the packing.