Buy article online - an online subscription or single-article purchase is required to access this article.
organic compounds
In the title compound, 2,3,6,7-tetrahydro-11-oxo-1H,5H,11H-[1]benzopyrano [6,7,8-ij]quinolizine-10-carboxylic acid, the coumarin moiety is planar. The two piperidine rings take flattened sofa conformations. There is an intramolecular hydrogen bond between the carbonyl group and the carboxyl group, and the hydrogen bond influences the bond lengths in the pyron ring. The crystal packing is governed by van der Waals forces.