The Synthesis Of Several Carbohydrate Drug Intermediates

In the area of medicinal chemistry, the research of carbohydrate drugs has been more and more attention. Pharmaceutical intermediates are basic of chemical pharmaceuticals by synthesis, development speed of carbohydrate drug intermediates determines the development of carbohydrate drugs to some extent. The synthesis of several carbohydrate drug intermediates were studied in this thesis.2,3,4,5,6-Pentabenzyl mannose is a important intermediate for synthesising KDO(3-Deoxy-D-manno-2-octulosonic acid) and D-mannoheptulose, which are carbohydrate drugs. Pentabenzyl mannose was prepared in two routes in this thesis. By utilizing D-mannitol as a raw material, through tritylation,benzylation,detritylation and Collins oxidation, pentabenzyl mannose was synthesized successfully in four steps for the first time. The total yield was 55%; Secondly, pentabenzyl mannose was synthesized by the following three steps: formation of a dithioacetal, benzylation, and cleavage of dithioacetal. The total yield was 31%. The two routes were compared from material cost, novelty and so on.Iodopropargyl derivatives not only are carbohydrate chemical intermediates, but also have the effect against fungal and bacteria. Iodopropargyl glycosides are new compounds, which were synthesized by propargylation, iodo from four aldoses, the total yield was 40-50%. Then, the four iodopropargyl glycosides were used for bioactivity assay, the results showed that iodopropargyl glycosides have the effect against fungal.Sucrose is a inexhaustible resource, a large number of intermediates can be preparated through different chemical reaction. Tetrabenzoyl glucose and Tetrabenzoyl fructose are intermediates derived from sucrose, which were preparated through benzoylation, acidolysis and hydrolyzation with sucrose as a raw material. The hydrolysis condition was changed to avoid using expensive reagent AgCO₃, The total yield was 54% and 49% respectively, which is higher than literature values.