In vivo antitumor, in vitro antibacterial activity and alkylating properties of phosphorohydrazine derivatives of coumarin and chromone.

Efficient acetalisation of aldehydes catalyzed by titanium tetrachloride in a basic medium

https://www.arkat-usa.org/get-file/53632/

Chemistry and application of 4-oxo-4H-1-benzopyran-3-carboxaldehyde

Synthesis of Coumarin Derivatives from 4-Oxo-4H-1-benzopyran-3-carboxaldehyde via 3-(Arylaminomethylene)chroman-2,4-dione

This review presents a survey of the condensations of 3-formylchromone with various active methylene and methyl compounds, e.g. malonic or barbituric acid derivatives, five-membered heterocycles, etc. The utilisation of the condensation products for the synthesis of different heterocyclic systems, which is based on the ability of the γ-pyrone ring to be opened by the nucleophilic attack is also reviewed. Finally, the applications of microwave irradiation as an unconventional method of reaction activation in the synthesis of condensation products is described and the biological activity of some chromone derivatives is noted.

https://www.mdpi.com/1420-3049/10/8/937/pdf

Reactions of 3-formylchromone with active methylene and methyl compounds and some subsequent reactions of the resulting condensation products.

Benzopyrans. 17. Triethylamine-mediated transformation of 4-oxo-4H-[1]benzopyran-3-carboxaldehyde

That the key step in the title reaction id the Diels–Alder addition of 3-acetylchromenone (1) to its acyl–acyl rearranged isomer (9′a) is supported by the formation of 2-salicyloylxanthone (5) from the reaction of (9) with any of the chromenones (1)—(4)

Base catalysed deacylative dimerisation of 3-acetylchromenone: a facile Diels–Alder reaction

Heterocyclic Systems; 151. Formation and Hydrolysis of the [4 + 2]-Cycloadduct of 4-Oxo-4H-[1]benzopyran-3-carboxaldehyde with Ethyl Vinyl Ether

The title dihydrofurans (3f, R1= H, Me, and Cl), prepared from the α-cyano-ester (1e) and diazomethane, thermally rearrange to the cyclopropanes (4f) in predominantly Z-isomeric form.

Thermal rearrangement of 4-cyano-2,3-dihydro-5-ethoxy-3-methyl-3-(4-oxo-4H-1- benzopyran-3-yl)furans: a reversed alkoxycarbonylcyclopropane → 5-alkoxy-2,3-dihydrofuran transformation

Thermal Rearrangement of 4-Cyano-2,3-dihydro-5-ethoxy-3-methyl-3-(4-oxo-4H-1-benzopyran-3-yl)furans: A Reversed Alkoxycarbonylcyclopropane → 5-Alkoxy-2,3-dihydrofuran Transformation.

Chandra Kanta Ghosh

Papers

Benzopyrans. 17. Triethylamine-mediated transformation of 4-oxo-4H-[1]benzopyran-3-carboxaldehyde

Base catalysed deacylative dimerisation of 3-acetylchromenone: a facile Diels–Alder reaction

Heterocyclic Systems; 151. Formation and Hydrolysis of the [4 + 2]-Cycloadduct of 4-Oxo-4H-[1]benzopyran-3-carboxaldehyde with Ethyl Vinyl Ether

Thermal rearrangement of 4-cyano-2,3-dihydro-5-ethoxy-3-methyl-3-(4-oxo-4H-1- benzopyran-3-yl)furans: a reversed alkoxycarbonylcyclopropane → 5-alkoxy-2,3-dihydrofuran transformation

Thermal Rearrangement of 4-Cyano-2,3-dihydro-5-ethoxy-3-methyl-3-(4-oxo-4H-1-benzopyran-3-yl)furans: A Reversed Alkoxycarbonylcyclopropane → 5-Alkoxy-2,3-dihydrofuran Transformation.