Photochemistry of flavonoids 5. photo cyclization of 2 styryl 4h chromen 4 ones
Yokoe, I.; Higuchi, K.; Shirataki, Y.; Komatsu, M.
Chemical and Pharmaceutical Bulletin 29(9): 2670-2674
1981
ISSN/ISBN: 0009-2363
Accession: 006110332
Irradiation of 2-styryl-4H-chromen-4-ones with a high pressure Hg lamp at room temperature under air gave benzo[a]xanthones. The cyclization of methoxy-substituted styrylchromones occurred at the para position relative to the OMe [methoxy] group on the styryl ring, whereas 2-[.beta.-(2-naphthyl)vinyl]chromone cyclized at the .alpha.-position of the naphthalene ring.