13-cis-5,6-Dihydro-5,6-epoxy retinoic acid, a degradation product formed when 13-cis-retinoic acid is exposed to light and/or atmospheric oxygen, has been synthesized and its molecular conformation and crystal structure have been investigated by X-ray single crystal diffraction. The geometry of the molecule is compared with that of previously acquired pure 13-cis-retinoic acid. The epoxy group is disordered over two adjacent cyclohexane bonds with different site-occupation factors. In the crystal, the molecules form centrosymmetric dimers through hydrogen bonds between carboxylic acid groups. The X-ray powder diffraction pattern, together with a list of the most prominent peaks, and the thermal analysis of the compound are also reported to better characterize the product.
Molecular and crystal characterization of 13-cis-5,6-dihydro-5,6-epoxy retinoic acid: a potential impurity of isotretinoin
MALPEZZI, LUCIANA;BRENNA, MARIA ELISABETTA;FUGANTI, CLAUDIO;
2002-01-01
Abstract
13-cis-5,6-Dihydro-5,6-epoxy retinoic acid, a degradation product formed when 13-cis-retinoic acid is exposed to light and/or atmospheric oxygen, has been synthesized and its molecular conformation and crystal structure have been investigated by X-ray single crystal diffraction. The geometry of the molecule is compared with that of previously acquired pure 13-cis-retinoic acid. The epoxy group is disordered over two adjacent cyclohexane bonds with different site-occupation factors. In the crystal, the molecules form centrosymmetric dimers through hydrogen bonds between carboxylic acid groups. The X-ray powder diffraction pattern, together with a list of the most prominent peaks, and the thermal analysis of the compound are also reported to better characterize the product.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
