Molecular design and utilization of hybid-functional cellulose derivatives

纤维素分子的结构特征是在重复的无水葡萄糖单元中有三个羟基。考虑到这些羟基的反应性，我们可以在单分子中设计出具有多种功能的高级纤维素衍生物。我们计划制备具有6-0位长链烷基的杂化功能纤维素衍生物，期望其溶解度和热性能得到改善，并且在2-和3-0位具有特殊功能。结果表明：1)以工业苯甲酸甲酯或对羟基二苯甲酮为原料，以关键中间体4-羟基三醇为原料，合成了具有不同烷基链长度的与纤维素6-0位发生区域选择性反应的诺贝尔醚化试剂4-烷基氧基三酰氯。2)发现新试剂与甲基a- d -葡萄糖或纤维素的6- o位有区域选择性反应。所得纤维素衍生物的溶解度提高，熔融时具有液晶性质。3)改进了制备纤维素用开环聚合单体的合成方法。反应步骤少，总产率高。从合成的角度来看，该单体的3- o - alli基团比苄基更有用。4)由开环聚合产物制备了所有可能的7种区域选择性甲基化纤维素。因此，该方法可用于制备具有长链的区域选择性取代的纤维素衍生物，该衍生物可转化为具有磁性或导电性的混合功能纤维素衍生物。

The structural feature of cellulose molecule is to have three hydroxyl groupsin the repeating anhydro glucose unit. Considering the reactivity of these hydroxyl groups enable us to open interesting possibilities to design advanced cellulose derivatives with multiple functions in the single molecule.We planned to preare a hybrid-functional cellulose derivatives with long chain alkyl group at 6-0-position expecting the improved solubility and thermal property, and special functions at 2- and 3-0-positions. The results are as follows:1) Nobel etherification reagents,4-alkyloxytrityl chlorides with different alkyl chain lengths which regioselectively reacts with 6-0-psition of cellulsoe, were synthesized from commercial methyl benzoate or p-hydroxybenzophenone via a key intermediate, 4-hydroxytrityl alcohol.2) The novel reagents were found to react regioselectively with 6-O-position of methyl a-D-glucose orcellulose. The obtained, cellulose derivatives showed improved solubility and melted with liquid crystalline property.3) The synthetic method of ring-opening polymerization monomer for preparing cellulose was improved to give.Higher overall yields with fewer reaction steps. 3-O-AllyI group of the monomer was indicated to be more useful than benzyl group from the synthetic point of view.4) All possible 7 regioselectively-methylated celluloses were prepared from the ring-opening polymerization products. Thus, the method can be applied for the preparation of regioselectivly-substituted cellulose derivatives with long chain, which may be converted hybrid-functional cellulose derivatives with magnetism or electro-conductivity.