Reaction Kinetics and Mechanism of Sulfuric Acid-Catalyzed Acetolysis of Acylated Methyl L-Ribofuranosides
作者:Jonas J. Forsman、Johan Wärnå、Dmitry Yu. Murzin、Reko Leino
DOI:10.1002/ejoc.200900889
日期:2009.11
The mechanism of the sulfuric acid-catalyzed acetolysis of methyl 2,3,5-tri-O-acetyl- and methyl 2,3,5-tri-O-benzoyl-L-ribofuranosides and the accompanying anomerization of both the starting material and the 1,2,3,5-tetra-O-acetyl- and 1-O-acetyl-2,3,5-tri-O-benzoyl-L-ribofuranoses formed was investigated. The progress of the reactions was followed by 1H NMR spectroscopy and the rate constants for
硫酸催化甲基 2,3,5-三-O-乙酰基-和甲基 2,3,5-三-O-苯甲酰基-L-呋喃核糖苷的乙酰化机理以及伴随的起始原料和研究了形成的 1,2,3,5-四-O-乙酰基-和 1-O-乙酰基-2,3,5-三-O-苯甲酰基-L-呋喃核糖。反应的进程由 1 H NMR 光谱跟踪,反应的速率常数被确定为建议的动力学模型。阐明了 H+ 和 Ac+ 作为催化活性物质的作用,证明酰化甲基呋喃糖苷的异构化是通过质子化激活的,而相反,1-O-乙酰基呋喃核糖的异构化是通过乙酰阳离子激活的.