Morphine hydro­chloride anhydrate

In the title mol­ecular salt [systematic name: (5α,6α)-7,8-didehydro-4,5-ep­oxy-17-methyl­morphinan-3,6-diol hydro­chloride], C₁₇H₂₀NO₃⁺·Cl⁻, the conformation of the morphinium ion is in agreement with the characteristics of the previously reported morphine forms [for example, Gylbert (1973). Acta Cryst. B29, 1630–1635]. In the crystal, the cations and chloride anions are linked into a helical chain propagating parallel to the b-axis direction by N—H...Cl and O—H...Cl hydrogen bonds. The title salt and the morphine monohydrate [Bye (1976) Acta Chem. Scand. 30, 549–554] display very similar one-dimensional packing modes of their morphine components.