Colouring matters of Australian plants. XXIV. Haemofluorone B : New synthetic models and a revised structure

Abstract

The occurrence of haemofluorone B in Anigozanthos rufus and Conostylis setosa has been confirmed. The revised structure 5,8,9-trihydroxy-3H-naphtho[2,1,8-mna]xanthen-3-one is now proposed for this pigment. Dihydroxyanigorufone has also been found in Conostylis setosa and the structure 9-(3,4-dihydroxyphenyl)-2-hydroxy-lH-phenalen-l-one has been confirmed by synthesis of the trimethyl ether. Some model arylphenalenones and naphthoxanthenones have been prepared fromnaphthylphenylpropanones and some unusual products have been obtained by photolysis of arylphenalenonesand by the reactions of Grignard reagents with phenalenones.