DEPROTECTION OF AN ACETAL BENZYLIDENE WITH A PHENOMENON OF EPIMERIZATION OF THE ANOMERIC CENTER OF A PYRAZOLO-PYRANOSOIDE DERIVATIVE

In order to study the reactivity of the pyranose part of the pyrazolo-pyranoside platform, we opted for an opening of the benzylidene acetal by an acid hydrolysis reaction. Unexpected platform reactivity at the anomeric carbon level was observed, resulting in a minority compound whose benzylidene is unchanged and a 4,6-diol whose ethoxy groups at the anomeric position are replaced by ethoxy groups.