Ceric Ammonium Nitrate/Pyridine: A Mild Reagent for the Selective Deprotection of Cyclic Acetals and Ketals in the Presence of Acid Labile Protecting Groups
The reagent system cericammoniumnitrate/pyridine can perform the cleavage of primary and (in some cases) secondary acetonides, benzylidenes and tetrahydropyranyl ethers. The mild acididity of the reaction system (pH 4.4) allows deprotections to be performed in the presence of several acid labile protecting groups.
Regioselective functionalization of monosaccharides is notoriously achieved using metal catalysis, lengthy protec-tion/deprotection-requiring synthetic strategies, various enzymes, or other methods that target cis-diols—all of which preclude their use with glucose derivatives. We report herein a new methodology using selected boronic acids as temporary protecting groups and describe its application
have studied the acyl migration in different monosaccharides using five different acylgroups by a combination of experimental, kinetic and theoretical tools. The results show that the anomeric configuration in the monosaccharide has a major influence on the migration rate, together with the relative configurations of the other hydroxylgroups and the nature of the migrating acylgroup. Full mechanistic