Synthesis Of 3-branched-chain Sugars And 3-amino Sugars From 3-keto Sugars Of D-xylose

In this thesis, the synthetic methods for the new branched-chain sugars, amino sugars and thiaztion sugars from 3-keto sugars of D-xylose have been investigated and established. Stereoselective synthesis of a series of 3-C-nitromethyl branched-chain sugars, 3-C-carbalkoxy branched sugars, 3-C-aminomethyl branched sugars, imino sugars, 3-deoxy amino sugars, 3, 6'-(2-amino) thiazine derivatives, C10 higher carbon sugar and other containing nitrogen or sulfenyl derivatives have been achieved successfully. In the course of synthetic studies, some novel approaches for the synthesis of branched sugars, nitrogen and sulfenyl derivatives have been founded from 3-keto sugars of D-xylose. The main results obtained are as follows:1. In the presence of KF, 3-C-branched ribofuranose were stereoselectively synthesized by the reactions of the nucleophilic reagents (nitromethane, nitroethane, diethyl malonate, dimethyl malonate) with compound 1 or 7, the absolute configurations of products were confirmed by the X-ray crystallographic analysis of 2. Compound 6 was obtained from branched-chain sugar 4 by biosynthesis reaction.2. Catalytic hydrogenation reaction was carried out under various conditions to give the branched amino sugar 11 and benzoyl transfer derivative 12 from 2, and the structure of 12 was elucidated by its X-ray crystallographic analysis and spectroscopic method. Some alkyl derivatives were synthesized via an addition and reduction reaction in one-pot, and 12 was also chosen as a material to prepare two imino sugar derivatives.The p-toluenesulfonate salt of imino sugar (22) was obtained by catalytic hydrogenation reaction from 3-C-nitromethyl ribofuranose 8, and the structure of 22 was confirmed by X-ray crystallographic analysis.3. Using DCC as a dehydration reagent, some higher fatty acid amides derivatives and higher fatty acyl derivatives were obtained by the reaction of compounds 11 or 12 with higher fatty acids, and two diacyl derivatives were obtained respectively.4. Three deoxy aryamino derivatives were obtained from the reaction of 3-keto sugars with arylamino followed by stereoselectively reduction with NaBH4, the absolute configuration was confirmed by X-ray crystallographic analysis of 47. As well as imidazoline derivative 48 was obtained from the reaction of 3-keto sugar with o-diaminobenzene, and the structure was confirmed by its X-ray analysis. 5. 3,6'-(2-amino) thiazine derivative 52 was stereoselectively synthesized by the reaction of keto-sugar 7 with thioureas. The method is a mild, simple, high stereoselective method. The structure of 52 was confirmed by its X-ray crystallographic analysis and spectroscopic method.6. In the presence of NH₂CONH₂, C10 higher carbon sugar was first steroselectively synthesized at room temperature from the keto-sugar 7. This reaction provides a simple method to synthesis of C10 higher carbon sugar.The reaction of 1 or 7 with other ureas were studied respectively, the products reduced with NaBH₄, some amino derivatives, thio derivatives were obtained. This research work laid down the foundations of synthesis of biologically active substances from D-xylose.In the presence of DCC, two higher fatty acid monoamides derivatives (64, 65) and two higher fatty acid diamides derivatives (66, 67) were obtained by the reaction of compounds 52 with higher fatty acid. In conclusion, in this study some methods for synthesis of thiazine derivatives, C10 higher carbon sugar were developed from 3-keto sugars of D-xylose. 63 new compounds were synthesized and characterized by ¹HNMR, ¹3CNMR, HRMS and IR spectra. The stereochemistry of 8 among them was confirmed by X-ray crystallographic analyses.