76006-83-2Relevant academic research and scientific papers
Studies in the Xanthone Series. Part 13. Structural and Synthetic Studies on Toxyloxanthone B
Cotterill, Phillip J.,Scheinmann, Feodor
, p. 2353 - 2357 (2007/10/02)
A re-consideration of the 1H n.m.r. data for toxyloxanthone B trimethyl ether and an unambiguous total synthesis both show that toxyloxanthone B has the 1,1-dimethylpyranoxanthone structure (1a) and not the 3,3-dimethylpyranoxanthone system (2) previously assigned.The synthesis is based on the preparation of 1,7-dihydroxy-3,5-dimethoxyxanthone (5) from cyclisation of a benzophenone precursor (3a) or (3b) and selective demethylations.A Claisen rearrangement of the 7-prop-2-ynyloxyxanthone (6) followed by cyclisation and methylation gives toxyloxanthone B trimethyl ether.
