11,20-Dihydroxy-3-oxopregna-1,4-dien-21-oic acid monohydrate

Abstract

The title compound, C21H28O5·H2O, is the hydrate of a steroid derivative and was obtained by degradation of solid prednisolone sodium phosphate. The six C atoms in ring A are nearly co-planar with a mean deviation of 0.015 Å. Rings B and C are both in chair conformations, while ring D has an envelope form. In the crystal, intermolecular O—H...O hydrogen-bonding interactions occur between the hydroxy groups, carbonyl O atoms and solvent water molecules, resulting in an overall three-dimensional structure.