56063-95-7

Upstream product

• 89024-06-6 3-Methoxy-2-(4-methoxy-phenyl)-8,8-dimethyl-7,8-dihydro-6H-pyrano[3,2-g]chromen-4-one 
• 77-78-1 dimethyl sulfate 
• 86414-56-4 3-hydroxy-2-(4-methoxyphenyl)-8,8-dimethyl-4H,8H-benzo<1,2-b:5,4-b'>dipyran-4-one 
• 19013-03-7 6-acetyl-7-hydroxy-2,2-dimethyl-1H-chromene 
• 88055-36-1 7-Hydroxy-8-(4'-methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2H,6H-benzo<1,2-b:5,4-b'>dipyran-6-one 
• 86977-99-3 1-(7-Hydroxy-2,2-dimethyl-chroman-6-yl)-3-(4-methoxy-phenyl)-propane-1,3-dione 
• 123-11-5 4-methoxy-benzaldehyde 

Relevant academic research and scientific papers

Performic Acid Oxidation of Dihydro-o-hydroxyaroylacetylbenzopyrans: A New Synthesis of Dihydropyranoflavonols and Their Dehydro Analogues

Performic acid oxidation of dihydro-o-hydroxyaroylacetylbenzopyrans (Ia-c and Va-c) in chloroform gives the dihydropyranoflavonols (IIa-c and VIa-c respectively).Methylation of IIa-b and VIa-b with dimethyl sulphate and aqueous sodium carbonate affords the corresponding dihydropyranomethoxyflavones (IIIa-b and VIIa-b) and benzylic bromination of IIIa-b and VIIa-b with N-bromosuccinimide followed by dehydrobromination with pyridine, affords the pyranomethoxyflavones (IVa-b and VIIIa-b respectively).

Synthesis of 2,2-Dimethyl-2H-pyran-fused Flavonols Using the Modified Algar-Flynn-Oyamada Reaction

6-Acetyl-2,2-dimethylchromenes when separately condensed with p-anisaldehyde in the presence of ethanolic NaOH and subsequently oxidized with alkaline hydrogen peroxide without isolating the intermediate chalcones afforded the corresponding 2,2-dimethyl-2H-pyran-fused flavonols respectively in good yields.Thus, flavonols having free 3-hydroxyl and fused with 2,2-dimethyl-2H-pyran can be synthesized easily.