Huang Sha, Miller Amanda K, Wu Weiming
Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, United States.
Tetrahedron Lett. 2009 Nov 25;50(47):6584-6585. doi: 10.1016/j.tetlet.2009.09.054.
Pyridinium ketones have been found to exist as hydrates and hemiacetals in considerable amount in aqueous and alcoholic solutions, respectively. The relative position of the pyridinium positive charge has a large effect on the equilibrium constants. The polar substituent constants, sigma*, of the pyridinium group substituted at different positions can be estimated from the hydration constants.
已发现吡啶酮在水溶液和醇溶液中分别大量以水合物和半缩醛形式存在。吡啶鎓正电荷的相对位置对平衡常数有很大影响。不同位置取代的吡啶基团的极性取代基常数sigma*可由水合常数估算得出。