104409-38-3Relevant academic research and scientific papers
THE SOLID STATE AND SOLUTION CONFORMATION OF 1,2-O-ALKYLIDENE-α-D-RIBOPYRANOSES. CHIRALITY ASSESSMENT OF PENTOSES FROM CRYSTALLOGRAPHIC TORSION ANGLES
Cano, Felix H.,Foces-Foces, C.,Jimenez-Barbero, Jesus,Alemany, Antonio,Bernabe, Manuel,Martin-Lomas, Martin
, p. 2539 - 2550 (1986)
The structure of 3,4-di-O-acetyl-1,2-O-(S)-(1-cyanoethylidene)-α-D-ribopyranose (1) has been determined from X-ray diffraction data and refined to a conventional R value of 0.050 for the 1259 observed reflexions (3 ? (I) criterion).The compound packs in the P212121 space group with Z = 4 and lattice parameters of a = 20.0157 (7), b = 10.0552 (2), and c = 7.0870 (1) Angstroem.The conformation of the pyranoid ring in the solid state can be described as chair 1C4 (D) and that of the dioxolane ring, as envelope E1.The use of configurational angles for characterization of pentoses is presented.NMR studies have been carried out to determine the major conformation in solution of 1 and its analogues 2 - 5.The results seem to indicate in all cases the presence of a conformational equilibrium between the chair-like, 1C4, and the boat-like, oS2 conformation, in agreement with the results obtained from molecular mechanics calculations.
