Nuclear oxidation in the flavones and related compounds - Part XIII. A discussion of the results
The results contained in the recent publications from this laboratory on the subject of nuclear oxidation in the flavones and related compounds are summed up. Originally the main interest was in the theory of biogenesis of anthoxanthins; the bearing of the results on the evolution of the various types of flavones and flavonols is therefore discussed in detail. This study has led to the development of considerably simplified methods of synthesis of all the naturally occurring substances with three and four hydroxyl groups in ring A and of the special though simpler compounds like primetin. The application of this oxidation method along with ethylation for the establishment of the structure of partial methyl ethers as well as glycosides is illustrated by a number of typical examples. Special mention is made of the interesting and novel cases like gardenin and pedicin.