Substantial formation of hydrates and hemiacetals from pyridinium ketones

✍ Scribed by Sha Huang; Amanda K. Miller; Weiming Wu

• Book ID: 104096960
• Publisher: Elsevier Science
• Year: 2009
• Tongue: French
• Weight: 160 KB
• Volume: 50
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2009.09.054

✦ Synopsis

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, r * , of the pyridinium group substituted at different positions can be estimated from the hydration constants.