97185-29-0

Upstream product

• 143885-61-4 7-hydroxy-6-(4'-methoxy)cinnamoyl-3,4-dihydro-2,2-dimethyl-2H-benzo(1,2b)pyran 
• 98192-30-4 1-(7-Hydroxy-2,2-dimethyl-chroman-6-yl)-3,3-dimethoxy-2-(4-methoxy-phenyl)-propan-1-one 
• 31273-58-2 1-(7-hydroxy-2,2-dimethylchroman-6-yl)ethanone 
• 97911-95-0 (7-Benzyloxy-2,2-dimethyl-chroman-6-yl)-[3-(4-methoxy-phenyl)-oxiranyl]-methanone 
• 97911-89-2 (E)-1-(7-Benzyloxy-2,2-dimethyl-chroman-6-yl)-3-(4-methoxy-phenyl)-propenone 

Downstream Products

• 63762-53-8 erythrinin A methyl ether 
• 97185-30-3 3(4'-hydroxy)phenyl-8,8-dimethyl-6,7-dihydro-4H,8H-benzo(1,2-b:5,4-b')dipyran-4-one 
• 63807-86-3 alpinumisoflavone 

Relevant academic research and scientific papers

Boron Trifluoride Etherate Catalysed Rearrangement of Dihydropyranochalcone Epoxides: Synthesis of Dihydropyranoisoflavones and Their Dehydro-analogs

6-Acetyl-7-hydroxy-2,2-dimethylchroman (I) and 6-acetyl-7-methoxy-2,2-dimethylchroman (II) on condensation with the arylaldehydes (IIIa-d) give the dihydropyranochalcones (IVa-f).The O-benzylated chalcones (Va-f) are oxidised with alkaline hydrogen peroxi

SYNTHESIS OF ERYTHRININ A, A NATURALLY OCCURING PYRANOISOFLAVONE

Erythrinin A (10) has been synthesised by the oxidative rearrangement of dihydropyranochalcone 1 with thallium(III)nitrate (TTN) in trimethyl orthoformate (TMOF) to the dimethyl acetal 2, followed by cyclisation to 3, demethylation to 6 and dehydrogenation.Compound 10 could also be obtained from chalcone 4 on similar rearrangement followed by cyclisation, demethoxymethylation and dehydrogenation.In another route, chalcone 7 was oxidatively rearranged with TTN in TMOF, to 8 which on treatment with HCl yielded 10.

THALLIUM(III) NITRATE MEDIATED SYNTHESIS OF ERYTHRININ-A, DIHYDROPYRANO- AND PYRANOISOFLAVONES

Oxidative rearrangement of dihydropyranochalcones using thallium(III) nitrate-trimethylorthoformate (TTN-TMOF) reagent followed by acid catalysed cyclization yields the corresponding dihydropyranoisoflavones in good yields.Dehydrogenation of these isoflavones gave pyranoisoflavones.Demethylation of isoflavone (7) followed by dehydrogenation gave erythrinin-A (16).