Crystal structure of meso-L-glycero-L-gulo-heptitol

Abstract

The crystal structure of the title compound (I) has been determined from three-dimensional diffractometer data. Crystals are monoclinic, space group P2₁/c, with unit cell parameters: a= 4.920(1). b= 17.1 86(3). c= 10.993(2)Å, β= 97.25(2)°, Z= 4. The structure was solved by direct methods and refined by full-matrix least-squares to R 0.044 for 1 373 independent reflections. The heptitol has a non-planar conformation with gauche arrangements round the bonds C(4)–C(5) and C(5)–C(6), a type not previously observed in alditols. All hydroxy-hydrogens except H (O7) are disordered over two positions. There are two alternative, centrosymmetrically-related hydrogenbonding schemes, each having a finite main chain extended in the direction of the b axis and a branched chain, combined at O(1).