benzofurans and 3-hydroxyflavone

Herein, we report the development of continuous flow photoreactors for large scale ESIPT-mediated [3+2]-photocycloaddition of 2-(p-methoxyphenyl)-3-hydroxyflavone and cinnamate-derived dipolarophiles. These reactors can be efficiently numbered up to increase throughput two orders of magnitude greater than the corresponding batch reactions.

Topics: Alkaloids; Benzofurans; Biological Products; Cinnamates; Cycloaddition Reaction; Flavonoids; Light; Photochemical Processes

Rocaglamides are bioactive natural compounds which have a cyclopenta[b]benzofuran core structure. The total synthesis of a reported natural product, 3'-hydroxymethylrocaglate (5), was achieved using [3 + 2] cycloaddition between 3-hydroxyflavone and methyl cinnamate. We also describe the synthesis of rocaglamide heterocycle derivatives and evaluate their Wnt signal inhibitory activities. Compounds 4, 5, 22a, 22b, 22c and 23c showed potent Wnt signal inhibitory activity.

Topics: Benzofurans; Biological Products; Cinnamates; Crystallography, X-Ray; Cycloaddition Reaction; Flavonoids; HEK293 Cells; Humans; Models, Molecular; Wnt Proteins; Wnt Signaling Pathway

We have previously reported development of biomimetic, asymmetric [3 + 2] photocycloadditions between 3-hydroxyflavones and cinnamate dipolarophiles to access (-)-rocaglamide and related natural products. Herein, we describe enantioselective syntheses of aglain cycloadducts leading to the first total syntheses and absolute configuration assignments of the aglain natural products (+)-ponapensin and (+)-elliptifoline.

Topics: Benzofurans; Flavonoids; Heterocyclic Compounds, 3-Ring; Molecular Conformation; Oxidation-Reduction; Photochemical Processes; Pyrroles; Stereoisomerism

Topics: Benzofurans; Biomimetics; Eukaryota; Flavonoids; HeLa Cells; Humans; Molecular Structure; Photochemistry; Protein Biosynthesis

A unified biomimetic approach to the aglain-forbaglin-rocaglamide classes of natural products is reported. The approach involves photogeneration of oxidopyryliums via excited-state intramolecular proton transfer (ESIPT) of 3-hydroxyflavones followed by [3+2] dipolar cycloaddition to the aglain core. An alpha-ketol (acyloin) rearrangement was employed to transform the aglain core to the rocaglamide framework. This approach was successfully used for the synthesis of the natural product (+/-)-methyl rocaglate.

Topics: Benzofurans; Biomimetic Materials; Flavonoids; Photochemistry; Pyridinium Compounds