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Diisopropylidenated a-D-glucofuranose (1) was oxidated with CrO;-Pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopro-pylidenated a-D-allofuranose (3 ). The yield of 3 increased by 8% than that with only oxidated prod-uct as reduction substrate. Benzoylated derivative of 3 was selectively hydrolyzed and dimesylated to synthesize 3-O-benzoyl-l ,2-O-isopropylidene-a-D-allofuranose (5) and its dimesylated deriva-tive respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by 'H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81. 8%. Oxidation, re-duction and other procedures were practical and had application potential.  相似文献   
2.
自主性学习旨在充分调动和发挥学生主体性,充分调动其自主学习的积极性和兴趣,使之不仅会学习,而且爱学习,并形成良好的锻炼习惯,同时在学习过程中使学生个性得到充分发展。在体育教学中,不同的学生在体能、技能和兴趣、爱好等方面存在差异,每个学生都有自己独特的个性,表现在学习上,就是每个学生都有达到相同目标的最适  相似文献   
3.
Diisopropylidenated α-D-glucofuranose (1) was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose ( 3). The yield of 3 increased by 8% than that with only oxidated product as reduction substrate. Benzoylated derivative of 3 was selectively nydrolyzed and dimesylated to synthesize 3-O-benzoyl-1 .2- O- isopropylidene-α-D-allofuranose ( 5 ) and its dimesylated derivative respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by ^1H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81.8%. Oxidation. reduction and other procedures were practical and had application potential.  相似文献   
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