Crystal and molecular structure of 6- C-(2-furyl)-1,2:3,4-di- O-isopropylidene-α- d- glycero- d- galacto-hexopyranose

Abstract

6- C-(2-Furyl)-1,2:3,4-di- O-isopropylidene-α- d- glycero- d- galacto-hexopyranose ( 1) has been investigated by X-ray diffraction methods. The crystals obtained from ethyl acetate-light petroleum were monoclinic, space group P2 1 ( Z = 2), with cell dimensions a = 13.796(2), b = 7.887(1), c = 8.035(1) Å, and β = 106.68(3)°. A four-circle, automatic STOE diffractometer was used for the collection of intensity data. Of 1600 reflection intensities, 1390 were of I > 2σ I and were used for refinement. The structure was solved by direct methods, and the atomic parameters were refined by the full-matrix, least-squares procedure, giving R 0.056. The pyranose ring in 1 adopts a hybrid twist-boat conformation (° T 2 + B 2,5).