Synthesis Of Novel Isoiminosugar From D-xylose

In this thesis, based on the review of the kinds and synthetic methods of the azasugars, and then the synthetic methods for the azasugars from D-xylose have been investigated and established. a series of azasugars have been stereoselectively synthesized using the new method. The preparation of unsaturated nitro-xylose which is intermediate were optimized, and the reduction of unsaturated nitro-xylose have been carried out. In addition, we have synthesized a precursor of cyclitol via Diels-Alder reaction. The main results obtained are as follows:1. Compound 1 was prepared from xylose after multi-step reaction, and then compounds 2,3 and 5 were synthesized via Mannich reaction. In the presence of TFA, compounds 2 and 3 were transformed into deprotection products, and then 6 and 7 were respectively prepared from the deprotection products by catalytic hydrogenation reaction.2. With xylose as raw material, compound 1 was prepared by multi-step reaction. Saturated nitro compound 8 was obtained by dehydration and reduction from compound 1. Five-membered azasugar was prepared from 8 by catalytic hydrogenation reaction. Compounds 11,14 and 15 were synthesized from 8 by Mannich reaction. 3. Precursor of cyclitol 16 was obtained in the process of reduced the unsaturated nitro-xylose, and then we also synthesized this compound at the conditions of base catalysis and heated.In the thesis,16 compounds were synthesized, and 15 compounds are new compounds, All the new compounds were characterized by HR-MS,1H NMR, 13C NMR, IR spectra.