Chemical syntheses of regiospecific substituted cellulose derivatives-solution for basic problem of cellulose chemistry

自从A. Payen将纤维素命名为天然纤维以来，对纤维素的研究已经进行了大约150年。但在生物合成与生物降解、晶体结构、聚合机理、化学反应性、构效关系等方面仍有几个基本问题需要解决。近年来，我们首次成功地采用步进法和开环聚合法合成了纤维素。这些合成方法使我们能够获得高区域选择性取代的纤维素衍生物，可用于解决上述几个基本问题。在本研究中，我们成功地在可能的7种甲基纤维素中制备了6种区域特异性甲基化的纤维素。根据合成甲基纤维素的光谱数据，建立了甲基纤维素取代基分布的测定方法。通过纤维素的羧甲基化和甲基化，我们发现了纤维素分子中三个羟基的反应性的新发现。这些结果提示分子间和分子内氢键可能对三个羟基的反应性产生新的影响。

Since A. Payen named cellulose for natural fiber, cellulose research has been carried out for about 150 years. However, there are still several basic problems which should be solved : biosynthesis and biodegradation, crystal structure, mercelization mechanism, chemical reactivity, structure-function relationship.Recently, we have succeeded in the first chemical synthesis of cellulose both by stepwise method and by the ring-opening polymerization of glucose orthoester. These synthetic methods enables us to obtain the high-regioselectively substituted cellulose derivatives which can used for the solution of the above several basic problems. In the present investigation, We succeeded in the preparation of 6 regiospecifically methylated celluloses in the possible 7 methyl celluloses. Based on the spectroscopic data of these synthetic methyl celluloses, we established the determination method for the substituent distribution of methyl celluloses. As the results of carboxymethylation and methylation of celluose, we found the new findings about the reactivity of three hydroxyl groups in cellulose molecule. These results suggest new possible effects of inter- and intramolecule hydrogen bondings on the reactivity of three hydroxyl groups.