%0 Journal Article %T Stable polymorph of morphineCAS number: 57¨C27¨C2. %A Thomas Gelbrich %A Doris E. Braun %A Ulrich J. Griesser %J Acta Crystallographica Section E %D 2013 %I International Union of Crystallography %R 10.1107/s1600536812048945 %X In the stable polymorph of the title compound, C17H19NO3 [systematic name: (5¦Á,6¦Á)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol], the molecular 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. Intermolecular O¡ªH...O hydrogen bonds link the molecules into helical chains parallel to the b axis. Intramolecular O¡ªH...O hydrogen bonds are also observed. %U http://scripts.iucr.org/cgi-bin/paper?S1600536812048945