NEUE SYNTHESE UND KRISTALLSTRUKTUR DER LEUCROSE

Article abstract of DOI:10.1016/0008-6215(89)84086-8

Boron trifluoride-catalyzed condensation of 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl fluoride (2) with 3,4-di-O-benzoyl-1,2-O-isopropylidene-β-D-fructopyranose (1) gave preferentially the α-D-(1->5)-linked disaccharide 8.Similarly, glycosylation of benzyl 1,3,4-tri-O-benzoyl-β-D-fructopyranoside (4) with 2 gave preponderantly a disaccharide derivative that, after cleavage of benzoyl as well as benzyl groups, afforded leucrose (5-O-α-D-glucopyranosyl-β-D-fructopyranose; 13).This crystallized in the orthorhombic space group P2₁2₁2₁ containing four sugar and four water molecules in the unit cell in two positions in the ratio of 4:1.As expected, both the fructopyranose and the glucopyranose rings adopted the ²C₅(D) or ⁴C₁(D) chair conformations, respectively.