Synthesis of Butyl-α and β-D-Glucopyranosides in the Presence of Dealuminated H–Y Faujasites: Kinetic Study, Mechanism, Stereoelectronic Effects, and Microreversibility Principle
作者:Jean-François Chapat、Annie Finiels、Jacques Joffre、Claude Moreau
DOI:10.1006/jcat.1999.2477
日期:1999.7
selectivity properties, reduces the amount of oligomers and increases the amount of β--glucopyranosides in a significant manner. The β/α anomeric ratios observed are then discussed in terms of stereoelectronic effects which are, according to the principle of microreversibility, of the same nature as those reported for the reverse reaction, i.e., hydrolysis of alkyl--glucopyranosides.
在各种脱铝的HY沸石上研究了葡萄糖与正丁醇之间的糖基化反应,Si / Al比为2.5到100。通过这种方式,丁基α-和β-葡萄糖呋喃糖苷和-吡喃糖苷很容易合成。温度范围为363至383 K,丁醇/葡萄糖比为5至40。通过对糖基化反应的系统研究,提出了涉及连续步骤和竞争步骤的动力学方案。丁基-葡萄糖基呋喃糖苷和丁基-葡萄糖基吡喃糖苷是主要产品,丁基-然后将葡糖呋喃糖苷定量转化为其吡喃糖苷形式。与它们的形状选择性性质相关的微孔催化剂的使用以显着方式减少了低聚物的量并增加了β--吡喃葡萄糖苷的量。然后根据立体电子效应讨论观察到的β/α异头物比例,根据微可逆性原理,该立体电子效应的性质与针对逆反应(即烷基-葡糖吡喃糖苷的水解)报道的性质相同。