To Xylose And Other Raw Materials, Pharmaceutical Intermediates Synthesis And Related Reactions,

This thesis consists of two parts. The first part has three points Firstly, the tetraacetyl-D-ribofuranose was synthesized as the following, by using the novel route from D-xylose based on study of reference carefully. To achieve the best condition, each step has been studied carefully , The yield is 99.5% from D-xylose to the compound(2) , and the yield of step two is 97.4%. the amount of NaBH4 was decreased greatly in the reduction of compound (5). The total yield of this seven steps is 42.90/a, and the target compound was identified by elemental analysis, IR, -NMR and C-NMR. Secondly, a novel type reaction was found in the process of preparation of compound (9) by using absolute benzene and PDC as oxidant. The new compounds (9) and (10) wer?characterized by elemental analysis IR,-NMR,C-NMR. and 2D.NMR. By the way, the mechanism was deduced as the following:. The compound (11) was firstly synthesized from l,2-O-isopropylidene-5- benzoate-D-erythro-pentfuranos-3-ulose and phenylene diamine. It was identified by IR-NMR and C-.NMR. Thirdly, the isomerization on carbon-4 of compound(S) was found, the process was clarified as the following by measuring NMR spectral in different solvents: phenylmethylpiperidine;which is an important intermediate of citirezine and other drugs,. was synthesized in the total yield Of72.7% by using a new route showed as the following: The best condition of each step was investigated. The structure of the last compound was confirmed by using spectroscopic methods.