6032-33-3Relevant academic research and scientific papers
Rates of Acidic and Alkaline Hydrolysis of Substituted Phenyl α- and βDMannopyranosides
Kyosaka, Shigehisa,Murata, Sanae,Tanaka, Mitsuya
, p. 3902 - 3905 (2007/10/02)
The rates of hydrolysis of substituted phenyl α- and β-D-mannopyranosides were measured in acidic and alkaline solutions.In 0.11 N hydrochloric acid solution, the α-mannosides were hydrolyzed faster than the corresponding β-anomers.The rates of hydrolysis for the α-mannosides were unaffected by substitution in the phenyl group (Hammett reaction constant ρ=-0.07+/-0.065 (S.D.)), and those for the β-mannosides were slightly enhanced by the introduction of electron-releasing substituents (ρ=-0.25+/-0.082).In sodium hydroxide solution, the α-mannosides liberated their aglycones, phenols, much faster than the corresponding β-anomers and the rates were enhanced by the introduction of electron-withdrawing substituents (ρ=+2.7+/-0.14 for the α-, +3.1+/-0.46 for the β-mannosides, each in 3.93 N NaOH).Phenyl α-mannoside was hydrolyzed much faster than phenyl β-glucoside, though both have trans-1,2 configuration, indicating the importance of a 1,2-diaxial orientation for the reaction. Keywords --- aryl α-mannopyranoside; aryl β-mannopyranoside; acid hydrolysis; alkaline hydrolysis; Hammett plot
