Novel methodology for the synthesis of xanthones

Abstract

In this MSc, novel methodology for the synthesis of xanthones and related compounds was discovered. It was found that treatment of (1,4-dimethoxynaphthalen-2-yl)(2- hydroxyphenyl)methanone with ceric ammonium nitrate (CAN) resulted in the formation of 12a-methoxy-5H-benzo[c]xanthene-5,7(12aH)-dione as the product. The structure was confirmed by X-ray crystallography. Exposure of a related compound (2,5-dimethoxyphenyl)(2-hydroxyphenyl)methanone to CAN afforded 2-methoxy-9H-xanthen-9-one as the major product with 4amethoxy- 2H-xanthene-2,9(4aH)-dione formed as the minor product. This reaction sequence has opened a new door for research into xanthone synthesis at the University of the Witwatersrand