Articles written in Proceedings – Section A
Volume 38 Issue 1 July 1953 pp 40-44
A general method for the preparation of 5-hydroxyflavone and its derivatives from the corresponding 5:7-dihydroxyflavones by the action of Raney nickel on the 7-tosyloxy derivatives is described. Thus chrysin has been converted into 5-hydroxyflavone, and galangin 3-methyl ether to 5-hydroxy-3-methoxyflavone.
Volume 38 Issue 2 August 1953 pp 161-175
Reduction of anthraquinone, 2-methylanthraquinone, 2-mercaptomethylanthraquinone (I),
Dehydrogenation of tetrahydro- and tetrahydromethylanthraquinones to the parent compounds was effected by several methods including treatment with iodine and sodium acetate in nitrobenzene and the action of activated alumina on a hexane solution. Treatment of tetrahydroanthraquinone with selenium dioxide at 170° gave a mixture of anthraquinone, α-hydroxyanthraquinone and quinizarin. Decahydroanthraflavone was dehydrogenated in two steps to Anthraflavone.
Volume 39 Issue 2 February 1954 pp 90-97
By Raney nickel hydrogenolysis of the 7-tosyl ester (V), 5:7-dihydroxy-3: 3′:4′-trimethoxyflavone (IV) has been converted into 5-hydroxy-3:3′:4′-trimethoxyflavone (VI). Persulphate oxidation of (VI) gave 5: 8-dihydroxy-3: 3′:4′-trimethoxyflavone (VII), which was demethylated to 3:5:8:3′:4′-pentahydroxyflavone (III) by means of aluminium bromide in benzene. This pentahydroxyflavone was different in its properties from ponderosin, the yellow colouring matter of