The synthesis of 6-hydroxy-flavonols has been effected by the Algar and Flynn oxidation of 2∶5-dihydroxy-, 2∶5∶2′-trihydroxy-, 2∶5∶4′-trihydroxy-chalkones and 6∶3′-dihydroxy- and 6∶4′-dimethoxy-flavanones by means of alkaline hydrogen peroxide. The flavonols obtained have been characterised by preparing their acetyl or methoxy derivatives. It is interesting to note that free hydroxyl group in either nucleus of the chalkone molecule does not lead to complications during the oxidation, the flavonols being obtained in good yield.