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。但目前仍有几个基本问题需要解决：生物合成与生物降解、晶体结构、丝化机理、化学反应活性、结构与功能的关系。最近，我们通过分步合成和葡萄糖原酯开环聚合两种方法首次成功地合成了纤维素。这些合成方法使我们能够获得高区域选择性的纤维素衍生物，可以用来解决上述几个基本问题。在本研究中，我们在可能的7个甲基纤维素酶中成功地制备了6个区域特异性甲基化纤维素酶。根据合成的甲基纤维素酶的光谱数据，建立了甲基纤维素酶取代基分布的测定方法。作为纤维素的羧甲基化和甲基化的结果，我们发现了关于纤维素分子中三个羟基的反应性的新发现。这些结果表明分子间和分子内氢键对三个羟基的反应性可能产生新的影响。

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.