Semisynthesis of prunetin, a bioactive O-methylated isoflavone from naringenin, by the sequential deacetylation of chalcone intermediates and oxidative rearrangement.

Prunetin (4',5-dihydroxy-7-methoxyisoflavone) was semisynthesized in 8 steps from readily available naringenin in 26% total yield. The key reaction was chemoenzymatic sequential deacetylation to 6'-acetoxy-2',4″-dihydroxy-4'-methoxychalcone, the in situ-formed precursor for thallium(III) nitrate-mediated oxidative rearrangement.
(© The Author(s) 2021. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)