title: Stable polymorph of morphine.
abstract: In the stable polymorph of the title compound, C17H19NO3 [systematic name: (5α,6α)-7,8-didehydro-4,5-ep-oxy-17-methyl-morphinan-3,6-diol], the mol-ecular conformation is in agreement with the characteristics of previously reported morphine forms. The molecule displays the typical T-shape and its piperidine ring adopts a slightly distorted chair conformation. Inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into helical chains parallel to the b axis. Intra-molecular O-H⋯O hydrogen bonds are also observed.
authors.affiliation: Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gelbrich
authors.forename: Doris E
authors.initials: DE
authors.lastname: Braun
authors.forename: Ulrich J
authors.initials: UJ
authors.lastname: Griesser