Efficient method for tetrahydropyranylation/depyranylation of phenols and alcohols using a solid acid catalyst with Wells–Dawson structure
作者:Gustavo P. Romanelli、Graciela Baronetti、Horacio J. Thomas、Juan C. Autino
DOI:10.1016/s0040-4039(02)01822-1
日期:2002.10
form 2-tetrahydropyranyl acetals of phenols and alcohols is reported. Wells–Dawson heteropolyacid catalyst is used both in bulk form or supported on silica, reaction conditions include room temperature and toluene as solvent. Fast deprotection of THP-acetals can be attained by mere change of the solvent using THF–1% MeOH. In both reactions the supportedcatalyst is easily recoverable and reusable,
Efficient Tetrahydropyranylation of Phenols and Alcohols Catalyzed by Supported Mo and W Keggin Heteropolyacids
作者:G. P. Romanelli、P. G. Vázquez、L. R. Pizzio、C. V. Cáceres、M. N. Blanco、J. C. Autino
DOI:10.1081/scc-120018695
日期:2003.1.5
Abstract The protection of phenols as tetrahydropyranyl acetals is studied using supported Keggin heteropolyacids as catalysts, specifically molybdophosphoric or tungstophosphoric acids supported on silica. Phenol tetrahydropyranyl acetals are obtained in short times at room temperature with excellent yields. Protection of alcohols is also performed under mild conditions using both supported heteropolyacids