Synthesis and characterization of a chiral Schiff base containing alpha-D-altropyranoside unit and its zinc(II) complex

摘要

A novel chiral Schiff base containing alpha-D-altropyranoside unit, methyl 4,6-O-benzylidene-3-deoxy-3-(2-salicylideneaminoethylamino)- alpha-D-altropyranoside (3, Me-Alt-NNOH), has been prepared. Treatment of zinc chloride with 3 in the presence of triethylamine afforded a five-coordinated zinc(II) complex [Zn(Me-Alt-NNO)Cl] (4). Both 3 and 4 have been characterized by infrared, H-1 NMR, C-13 NMR, MS, and elemental analysis. The crystal structure of 4 has been determined by X-ray diffraction. Crystal structure analysis shows that the complex 4 exits a distorted triangular bipyramid geometry and the Schiff base motif acts as a uninegatively charged tetradentate chelating agent. The methoxy and amino groups cis-chelate to the zinc atom and the pyrano-ring is in an ideal C-4(1) chair conformation.