作者:Laurent Bischoff、Rabah Azzouz、Marc-Henri Fouquet、Francis Marsais
DOI:10.1055/s-2005-918916
日期:——
We report that the tetrahydropyranylation of hydroxyl groups, exhibiting especially very low nucleophilicities, can be achieved by means of Mitsunobu reaction with 2-hydroxytetrahydropyran. This reaction led to the protection of phenols and pyridinols without the use of an acidic catalyst. For instance hydroxypyridines could not be protected by dihydropyran under acidic conditions, whereas they underwent a smooth tetrahydropyranylation under Mitsunobu conditions. The method is selective for a phenol over an alcohol.
我们报告称,具有非常低亲核性的羟基的四氢糠醇化反应可以通过与2-羟基四氢糠醇的Mitsunobu反应实现。该反应可以在不使用酸催化剂的情况下保护酚类和吡啶醇。例如,在酸性条件下,羟基吡啶无法通过二氢糠醇进行保护,而在Mitsunobu条件下则能顺利进行四氢糠醇化。该方法对酚类相对于醇类具有选择性。