CRYSTAL AND MOLECULAR-STRUCTURE OF (+)-6,7-8,9-10,11-TRI-O-ISOPROPYLIDENE-2,3-DIDEOXY-D-ARABINO-L-ALLO-UNDEC-2-ENONO-1,4-LACTONE, C20H30O9

The crystal structure of the title lactone, C20H30O9, a potential precursor of uncommon 11-carbon sugar derivatives, has been determined by single-crystal diffraction methods. The compound crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 15.581(3), b = 14.047(2), c = 9.888(2) angstrom, and Z = 4. The structure was solved by direct methods and refined by full-matrix least-squares to R = 0.054. The absolute configuration of the seven stereogenic carbon atoms was deduced as 4R, 5R, 6R, 7R, 8S, 9R, 10R, being (R)-(+)-glyceraldehyde its progenitor. An intramolecular O-H ... O hydrogen bond is present. Weak interaction C-H ... O links the molecules in sheets parallel to the (100) plane.