J. Krajewski, P. Gluziński, Z. Urbańczyk-Lipkowska
Apr 1, 1986
Citations
0
Influential Citations
17
Citations
Journal
Carbohydrate Research
Abstract
Abstract 1,2:3,4-Di- O -isopropylidene-6- O -toluene- p -sulfonyl-α- d -galactopyranose has been investigated by X-ray diffraction methods. The crystals are orthorhombic, space group P 2 1 2 1 2 1 Z = 4) with cell dimensions a = 15.210(2), b = 15.658(2), and c = 8.858(1) A. The structure was solved by direct methods and the atomic parameters were refined anisotropically against 1030 observed reflections by a full-matrix, least-squares procedure giving R 0.039. The pyranoid ring has a twist (° T 2 ) conformation. The 1,2- and 3,4-dioxolane rings were assigned the 3 E and 2 T 1 conformations, respectively. Models of the di- O -isopropylidenegalactopyranose system with minimised strain energy were compared conformationally with several experimental structures containing the above ring systems.