Glucosidation of 2-hydroxy- and 5-hydroxy-1,4-naphthoquinone

Using the Koenigs-Knorr method two isomeric monohydroxynaphthoquinones were glucosidized, i.e. 2-hydroxy-1,4-naphthoquinone (lawson, Ia ) and 5-hydroxy-1,4-naphthoquinone (juglone, IIa ). The structure of the corresponding glucosides Ib and IIb was proved by 1 H NMR, mass, UV, VIS and IR spectra.