Co-Crystallization of Stereoisomers of N,N'-Bis(2-phenyl-5-hydroxymethyl-1,3-dioxan-5-yl)ethanediamide
作者:J. N. Ross、J. L. Wardell、J. N. Low、G. Ferguson
DOI:10.1107/s0108270195014478
日期:1996.1.15
X-ray analysis has revealed that two stereoisomers of the title compound, C24H28N2O8, co-crystallize in form (I). The unit cell of (I) contains equal numbers of the N,N'-bis(trans-2-phenyl-5-hydroxymethyl-1,3-dioxan-5-yl)ethanediamide, (Ia), and the N,N'-bis(cis-2-phenyl-5-hydroxymethyl-1 ,3-dioxan-5-yl)ethanediamide, (Ib), stereoisomers, each lying about crystallographic inversion centres. Fractional crystallization of the first mother liquor afforded crystals (II) containing only molecules of stereoisomer (Ia), also with crystallographic inversion symmetry. The stereoisomer (Ia) is Z-shaped in (I) and (II), whereas (Ib) is maximally extended. In both (I) and (II), the molecules are linked about inversion centres by O-H ... O hydrogen bonds.