Selective deacetylation of anomeric acetates using zinc acetate

Protected 1-hydroxy sugar units (glycosyl hemiacetals) have been used to obtain significant glycosyl donor compounds like glycosyl iodide and trichloracetamidates. They are important intermediates in the synthesis of oligosaccharides and phenolic glycosides.Acetylated 1-hydroxy sugar units were obtained by selective anomeric deacetylation of fully acetylated sugar derivatives. For this purpose mostly basic and some acidic reagents and enzymatic methods were used.In this study, an alternative method was developed for the selective anomeric deacetylation of fully acetylated sugar derivatives. Acetylated glucose, mannose, rhamnose and cellebiose were selectively deacetylated at 55-60 oC during 2-3 hours in methanol using zinc acetate as a catalyst with a yield of 70-80 %. Also, it was determined that the same reaction was done at room temperature after 24 hours with the same yield almostly. In conclusion, anomeric O-acetyl goups were selectively removed by using an highly useful method.