Wang Shao-Min, Zhu Wei-Guo, Kang Jian-Xun, Liu Hong-Min, Chen Jun-Miao, Li Cui-Ping, Zhang Kai
Department of Chemistry, Zhengzhou University, 100 Science Road, 450001 Zhengzhou, China.
Carbohydr Res. 2011 Feb 1;346(2):203-9. doi: 10.1016/j.carres.2010.11.018. Epub 2010 Nov 21.
The reaction process for the selective deprotection of acetylated glucosides by dibutyltin oxide in methanol is investigated by using methyl 2,3,4,6-tetra-O-acetyl-α-d-glucopyranoside as a model substrate with ESIMS and NMR techniques. According to the results, it is inferred that at first, dimeric 1,3-dimethoxytetrabutyldistannoxane is formed by the reaction of dibutyltin oxide with methanol, and then the tetraorganodistannoxane reacts with the acetylated glucoside to produce glucoside-organotin complex intermediates. Finally, the complex intermediates are hydrolyzed leading to the free-OH glucoside and organotin acetate derivatives. The reaction is affected by neighboring group participation and steric hindrance, which allow for high selectivities among different acetyl groups in acetylated glucosides.
以2,3,4,6-四-O-乙酰基-α-D-吡喃葡萄糖苷甲酯为模型底物，采用电喷雾离子化质谱（ESIMS）和核磁共振（NMR）技术，研究了二丁基氧化锡在甲醇中对乙酰化葡萄糖苷进行选择性脱保护的反应过程。根据实验结果推断，首先，二丁基氧化锡与甲醇反应生成二聚体1,3-二甲氧基四丁基二锡氧烷，然后该四有机二锡氧烷与乙酰化葡萄糖苷反应生成葡萄糖苷-有机锡络合物中间体。最后，络合物中间体发生水解，生成游离羟基葡萄糖苷和乙酸有机锡衍生物。该反应受邻基参与和空间位阻的影响，使得乙酰化葡萄糖苷中不同乙酰基之间具有较高的选择性。
