Indium Trichloride Mediated Cleavage of Acetonides in the Presence of Acid-Labile Functional Groups Enhancing the Synthetic Utility of 1,3-Dioxolanyl-Substituted 1,2-Oxazines.
F. Pfrengle, V. Dekaris, L. Schefzig, R. Zimmer, H.-U. Reissig, – 2008
Indium trichloride in an acetonitrile-water mixture chemoselectively cleaved the isopropylidene acetals of various 1,3-dioxolanyl-substituted 1,2-oxazines as well as carbohydrate derivatives. Deprotection of acetonides can be achieved in substrates susceptible for acid-induced cyclizations. Most importantly, enol ether moieties are not attacked and the presence of glycosidic linkages or acid-sensitive protecting groups such as tert-butyldimethylsilyl, 2-(trimethylsilyl)ethyl, or tert-butoxycarbonyl is also tolerated.