The Crystal and Molecular Structure of 3-Chloro-3-deoxy-1,2;5,6-di-O-isopropylidene-β-D-idose

The crystal and molecular structure of 3-chloro-3-deoxy-1,2;5,6-di-O-isopropylidene-β-D-idose has been determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.7% for the 817 observed reflections. The compound crystallizes in the orthorhombic space group P212121 with four molecules in a cell of dimensions a = 9.744(6), b = 26.76(2), c = 5.403(3) A.The structure analysis has served to confirm the site of halogenation and that it occurs stereospecifically. The conformation of the furan ring is an envelope arrangement with C(4) displaced from the mean plane.