K. Harata et al., CRYSTAL-STRUCTURE OF 6-0-[(R)-2-HYDROXYPROPYL]CYCLOMALTOHEPTAOSE AND 6-0-[(S)-2-HYDROXYPROPYL]CYCLOMALTOHEPTAOSE, Carbohydrate research, 247, 1993, pp. 83-98
Crystal structures of 6-O-[(R)-2-hydroxypropyl]- and 6-O-[(S)-2-hydrox
ypropyl)-cyclomaltoheptaose were determined by X-ray analysis. In both
structures, the 2-hydroxypropyl group is inserted into the macrocycli
c cavity of the next molecule related by the two-fold screw axis, and
a helically extended polymeric structure is formed by repetition of th
e intermolecular inclusion. The hydroxyl group of the substituent grou
p penetrates through the macrocyclic ring from the secondary hydroxyl
side and is linked to an HO-6 group by a hydrogen bond. Comparison of
intermolecular contacts of the substituent group indicates that the (S
)-2-hydroxypropyl group is better fitted to the cavity than the (R)-2-
hydroxypropyl group.