SYNTHESIS AND CONFORMATIONAL-ANALYSIS OF THE AMADORI COMPOUND N-(2,3 DENE-1-DEOXY-BETA-D-FRUCTOPYRANOS-1-YL)-L-TYROSINE BENZYL ESTER/

The title compound, a precursor in the synthesis of other analogues of Amadori type, was prepared and characterized by X-ray structure analy sis and NMR spectroscopy. The molecule crystallized in the orthorhombi c space group P2(1)2(1)2(1) with a = 10.441(2), b = 10.894(2), c = 24. 686(4)Angstrom, Z = 4. The molecule is flexible even in solid state; a t 100 K two orientations of the benzyloxy group are present in the uni t cell. Therefore, molecular mechanics and molecular dynamics simulati ons were used to study its conformational changes. The results obtaine d were compared with experimental observations. The comparative analys is revealed that the two conformers detected in the crystal are differ ent from the energetically favourable conformations in Me(2)SO solutio ns. Rotations about both C-N bonds affect the global molecular conform ation. The beta-D-fructopyranose moiety blocked with two dioxolane rin gs is the less flexible part of the molecule; in the solid state and i n Me(2)SO-d(6) it is in the skew conformation.