Structure and synthesis of arnottin I: a 6H-benzo[d]naphtho[1, 2-b]pyran-6-one derivative from a plant source

Arnottin I 2 isolated from Xanthoxylum arnottianum Maxim and of previously unknown structure has been unambiguously synthesized utilizing a 2-methylarenofuran as a masked salicylaldehyde. This is the first occurrence of a 6H-benzo[d]naphtho[1, 2-b]pyran-6-one derivative, the same skeleton as that of gilvocarsin-type antibiotics showing antitumour activity, from a plant source.