Stereso-selective Synthesis Of 3-deoxy-3-amino Sugars And C-branched Chain Sugars

In this thesis, use for 5-O-benzoyl-l,2-O-isopropylidene-a-D-erythro-3-pentosulofuranose in synthetic methodology was discussed. Through studying on the nucleophilic addition of anilines to 5-O-benzoyl-l,2-O-isopropylidene-a-D-erythro-3-pentosulofuranose, some new ammo sugar analogues were obtained. Furthermore, 3-methylnitro ribofuranose and methyl 2-nitromethyl-2-deoxy a-D-mannopyranoside, which are important branched sugars, were prepared with highly stereoselectivity through Henry reaction. The main results obtained are as follows.1. 3-methylnitro ribofuranoside and 2-methylnitro mannopyranoside were stereo-selective by Henry reaction, which were reduced to C-branched chain amino sugars in almost pure and comparable yield. This reaction provides an efficient method for reduction of aliphatic nitro compounds, especially the nitro group in unstable sugar ring. A new approach is developed to synthesis branched-chain sugar and azasugar. All of the compounds were characterized by IR, NMR, MS, HMBC and HMQC spectra.2. The stereospecific reduction of C=N double bond has been also studied. When the compounds were reduced by sodium borohydride, five of 3-deoxy-3-arylamino sugars were achieved. And the chloridization of 5-OH in 3-deoxy -3- arylamino sugar led to the important synthon of azasugar. The configuration of the product was elucidated by the X-ray diffraction analysis. This reaction provides a new way to synthesis amino sugar derivatives which are the candidate of glucosidase inhibitor. In consideration of that the substrate we used was the most abundant D-xylose, this synthesis was more convenient to the others reported. All of the compounds were characterized by IR, NMR and MS spectra.In summary, in this study a new method was developed for synthesis of amino sugars, branched-chain sugars and heterocycle compounds from 3-pentosulofuranose and 2 - keto a -D - glucopyranoside. Twelve new compounds were prepared in the work, and the structures were all characterized by IR, 'H-NMR, 13C-NMR and MS spectra.