Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps

Various cascade routes starting from D-galactose derivatives—via 6-CH₂OH oxidation catalyzed by galactose oxidase—are reported as one-pot procedures. The approach consists of combined bio- and chemocatalytic reactions as well as “spontaneous” chemical conversions. Workup is avoided by using compatible aqueous reaction conditions for all the consecutive reactions involved. A great benefit of this method is that D-galactose containing di-, tri- and oligosaccharides can be modified without the use of protecting groups and without any isolation and/or purification of intermediate products in these syntheses. The one-pot cascades, consisting of up to five consecutive transformations, gave rapid access to more than 40 uronic acid, amino sugar and deoxy sugar derivatives through enzymatic, homogeneous and heterogeneous catalytic conversions in water under mild conditions.