131086-97-0Relevant articles and documents
Domino reactions of 1,3-bis-silyl enol ethers with benzopyrylium triflates: Efficient synthesis of fluorescent 6H-benzo[c]chromen-6-ones, dibenzo[c,d]chromen-6-ones, and 2,3-dihydro-1H-4,6-dioxachrysen-5-ones
Appel, Bettina,Saleh, Nehad N.R.,Langer, Peter
, p. 1221 - 1236 (2007/10/03)
The condensation of 1,3-bissilyl enol ethers with benzopyrylium triflates, generated in situ by the reaction of chromones with Me3SiOTf, afforded functionalized 2,3-dihydrobenzopyrans; treatment of the latter with NEt3, or BBr3
Sequential Directed Ortho Metalation-Boronic Acid Cross-Coupling Reactions. A General Regiospecific Route to Oxygenated Dibenzopyran-6-ones Related to Ellagic Acid
Alo, B. I.,Kandil, A.,Patil, P. A.,Sharp, M. J.,Siddiqui, M. A.,et al.
, p. 3763 - 3768 (2007/10/02)
A general regiospecific synthesis of dibenzopyran-6-one derivatives 1a,c and 8a-i related to ellagic acid is described (Scheme I, Table I).The sequence involves directed ortho metalation-boronation of benzamides 4 to give the arylboronic acids 5, which, upon palladium-catalyzed cross-coupling with alkoxybromobenzenes 6 leads to the biphenylamides 7.BBr3 demethylation followed by acid-catalyzed cyclization affords pyranone 8.In this manner, the naturally occurring dibenzopyranones 1a, autumnariol (1c), and the heterocyclic analogue 13 (Scheme III) were efficiently prepared.