【作者】 祁世波；

【导师】 张卫红；

【作者基本信息】 天津大学 ， 应用化学， 2007， 硕士

【摘要】 本文以α-D-葡萄糖为原料,经过丙酮保护、PDC(重铬酸吡啶盐)氧化-硼氢化钠还原、酸选择性水解、高碘酸钠氧化降解、甲氧胺醛基保护、DDQ(二氯二氰基苯醌)完全水解-硼氢化钠还原及三氯化钛脱肟等九步反应合成了L-核糖,重点对PDC氧化、高碘酸钠氧化降解、甲氧胺醛基保护反应进行了研究。研究了葡萄糖的羟基保护反应,以丙酮-浓硫酸体系对α-D-葡萄糖进行异丙叉化,合成1,2:5,6-氧-二异丙叉基-α-D-呋喃葡萄糖(2),重结晶后收率为38%。研究了以氧化还原方法改变糖的羟基构型的方法,以2为原料,以PDC-醋酐-二氯甲烷体系氧化,再进行硼氢化钠还原,改变了C-3上羟基构型,得到1,2:5,6-氧-二异丙叉基-α-D-呋喃阿洛糖(3),两步收率为70%。研究了氧化剂PDC的制备方法。研究了阿洛糖衍生物3的异丙叉基选择性水解反应,以硫酸-甲醇体系进行水解反应,合成1,2-氧-异丙叉基-α-D-呋喃阿洛糖(4),收率为92.2%。研究了选择性水解产物4的氧化降解反应,在高碘酸钠-碳酸氢钠-水体系进行氧化降解,合成1,2-氧-异丙叉基-α-D-核糖-戊二醛-1,4-呋喃糖(5),收率为86.9%。研究了氧化降解物5的醛基保护反应,分别以羟胺-甲醇、乙硫醇-盐酸、甲氧胺-甲醇体系进行醛基保护反应,确定了以甲氧胺为醛基保护试剂,合成1,2-氧-异丙叉基-α-D-核糖-戊二醛-1,4-呋喃糖-氧-甲基肟(6c),收率为73.6%。研究了醛基保护物6c的全水解-还原反应,以6c为原料,以DDQ-乙腈体系进行全水解,再进行硼氢化钠还原,合成L-核糖-氧-甲基肟(7c),两步收率为79%。初步研究了甲基肟7c的脱保护反应,以三氯化钛-四氢呋喃体系进行脱保合成L-核糖(8),收率为23.9%。九步反应的总收率为2.9%,除了最后一步其它各步均未采用柱分离方法,并用1H-NMR对各步产物进行了表征。更多还原

【Abstract】 Withα-D-glucose as starting material, L-ribose was synthesized by nine step reactions such as acetone protection, PDC (pyridinium dichromate) oxidation-NaBH4 reduction, acid selective hydrolysis, NaIO4 oxidative degradation, aldehyde group protection with methoxyl amine, DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) thorough hydrolysis- NaBH4 reduction and deoximation with titanium trichloride .Particularly, PDC oxidation method, NaIO4 oxidative degradation method and aldehyde group protection with methoxyl amine method were studied intensively. The hydroxyl group protecting reactions ofα-D-gluofuranose was studied. The isopropylidenation reaction ofα-D-gluofuranose was carried to synthesis 1,2:5,6-O-diisopropylidene-α-D-gluofuranose (2) with acetone-conc. H2SO4 system, by crystallization, the yield was 38%. Hydroxyl group stereo structure conversion in sugar was studied. The C-3 position hydroxyl group stereo structure of 2 was converted by PDC-Ac2O-CH2Cl2 oxidation and NaBH4 reduction, Thus 1,2:5,6-O-diisopropylidene-α-D-allofuranose (3) was synthesized, two steps overall yield was 70%. The preparation method of PDC was studied.Selective hydrolysis reaction ofα-D-allofuranose derivative 3 was studied. The selective hydrolysis reaction of 3 was carried to synthesize 1,2-O-isopropylidene-α-D-allofuranose (4) with dilute H2SO4–CH3OH, the yield was 92.2%. Oxidative degradation reaction of 4 was studied. The hydrolysis product 4 was carbon-decreasing oxidated with NaIO4-NaHCO3-H2O system. Thus 1,2-O-isopropylidene-α-D-ribo-pentodialdo-1,4-furanose (5) was synthesized , the yield was 86.9%. Aldehyde group protection reaction ofα-D-ribose derivative 5 was studied. The reaction was carried out with NH2OH-CH3OH system, CH3CH2SH-HCl system and NH2OCH3- CH3OH system. The methoxyl amine was determined as aldehyde group protection reagent. Thus 1,2-O-isopropylidene-α-D-ribo- pentodialdo-1,4-furanose-O-methyl-oxime (6c) was synthesized, the yield was 73.6%.Thorough hydrolysis- reduction reaction of 6c was studied. The diversion was converted by DDQ-CH3CN thorough hydrolysis and NaBH4 reduction. Thus L-ribose-O-methyl-oxime (7c) was synthesized, two steps overall yield was 79%. Deoximation reaction of the oxime 7c was studied premilinarily. The reaction of 7c was carried out to synthesize L-ribose (8) with TiCl3-THF system, the yield was 23.9%. Nine steps overall yield was 2.9%. Except the final step, no column chromatography separating method was applied in each step in all nine steps, Each step product was characterized with 1H-NMR.更多还原