Study On The Synthesis And Application Of D-Allose And Its Derivatives

With α -D-glucose as starting material, D-allose and five D-allofuranose derivatives and epimers were prepared. Some was applied in carbon-decreasing oxidation. Particularly, hydroxyl group protection, hydroxyl group stereo structure conversion by oxidation / reduction method and isopropylidene group selective hydrolysis methods were studied intensively. They were described as the following:1. The hydroxyl group protecting reactions of D-glucofuranose and D-allofuranose derivatives were studied. The practical methods of isopropylidenation, benzoylation and mesylation were obtained. The isopropylidenation reaction of α -D-glucose was carried out to synthesis l,2:5,6-O-diisopropylidene- α -D-glucofuranose (2) with acetone — conc. H₂SO₄ — Na₂SO₄ system and new 2,2-dimethoxylpropane — p-toluenesulfonic acid system respectively. Solid α -D-glucose and 2 were characterized by solid-state ¹H-NMR spectra. α -D-allofuranose benzoylated derivative 9 was synthesized from isopropylidenated α -D-allofuranose derivative 4 by benzoylation. Mesylated derivative 10 of α -D-allofuranose was synthesized from isopropylidenated α -D-allofuranose derivative 9 by mesylation.2. Hydroxyl group stereo structure conversion in sugar was studied. The 3-position hydroxyl group stereo structure of diisopropylidenated α -D-glucofuranose derivative 2 was converted by CrO₃-pyridine-acetic anhydride oxidation and NaBH₄ reduction. Thus diisopropylidenated α -D-allofuranose derivative 4 was synthesized. Two steps overall yield was 57.4%. The feachers and the conditions of oxidation and reduction were discussed. The hydrate of the oxidation product 3 was separated and characterized. The practical short column chromatography separating method, reduction method for 3 and its hydrate mixture were obtained.3. The mechanism and feachers of isopropylidene group selective hydrolysis reaction with α -D-allo-and α -D-glucofuranose derivatives were discussed. Two practical methods with inorganic acid catalyst and new ion-exchange resin catalyst were obtained. The α -D-allofuranose derivatives or their epimers with one isopropylidene group 1,2-O-isopropylidene α-D-allofuranose (6), 1,2-0-isopropyl--idene- α -D-glucofuranose (7) and 3-O-benzoyl-1,2-O-isopropylidene- α -D-allofura--nose (9) were synthesized. D-allose (5) was synthesized from 4 by complete hydrolysis. The selective hydrolysis intermediate l,2-O-isopropylidene-5-hydroxyl--isopropyl- a -D-allofuranose was separated and characterized by JH- and 13C-NMR. The relationship of different hydrolysis substrates structures and their hydrolysis selectivity was discussed. The stronger the electron -withdrawing ability of 3-positon substituted group, the higher the hydrolysis selectivity of diisopropylidenated a -D-allofuranose derivative.4. The preliminary application of D-allofuranose derivatives was carried out. 1,2-O-isopropylidene a -D-allofuranose (6) was carbon-decreasing oxidated with silica gel-NaIO4-THF system. Thus 1,2-O-isopropylidene a -D-ribofuranose-5-al (11) was synthesized.In each step, the intermediates and target D-allose derivatives obtained in this paper were characterized by 'H-NMR spectra and methods.