104481-01-8

Upstream product

• 104481-00-7 1-(6-hydroxy-2,4-dimethoxy-3-methoxymethoxyphenyl)-ethanone 
• 6962-57-8 3,6-dihydroxy-2,4-dimethoxyacetophenone 
• 1486-54-0 3,4-dibenzyloxybenzoyl chloride 

Downstream Products

• 170234-91-0 2-(3,4-Bis-benzyloxy-phenyl)-5,7-dimethoxy-6-methoxymethoxy-chromen-4-one 
• 104481-06-3 Acetic acid (2S,3R,4S,5R,6R)-4,5-diacetoxy-6-acetoxymethyl-2-[5-benzyloxy-2-(3,4-bis-benzyloxy-phenyl)-7-methoxy-4-oxo-4H-chromen-6-yloxy]-tetrahydro-pyran-3-yl ester 
• 104481-07-4 5-Benzyloxy-2-(3,4-bis-benzyloxy-phenyl)-7-methoxy-6-((2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-hydroxymethyl-tetrahydro-pyran-2-yloxy)-chromen-4-one 
• 104481-04-1 6-acetoxy-3',4',5-tris(benzyloxy)-7-dimethoxyflavone 
• 104481-05-2 6-hydroxy-3',4',5-tris(benzyloxy)-7-dimethoxyflavone 
• 104495-50-3 6-acetoxy-3',4'-bis(benzyloxy)-5,7-dimethoxyflavone 
• 104481-02-9 6-acetoxy-3',4'-bis(benzyloxy)-5-hydroxy-7-dimethoxyflavone 
• 104481-03-0 3',4'-bis(benzyloxy)-5,6-dihydroxy-7-dimethoxyflavone 
• 27181-96-0 3',4'-bis(benzyloxy)-6-hydroxy-5,7-dimethoxyflavone 

Relevant academic research and scientific papers

Studies of the selective O-alkylation and dealkylation of flavonoids. XVIII. A convenient method for synthesizing 3,5,6,7-tetrahydroxyflavones

In the demethylation of 6-hydroxy-3,4',7-trimethoxy-5-(tosyloxy)flavone with anhydrous aluminum bromide, the 5-tosyloxyl group was eliminated with bromination to give 8-bromo-3,6,7-trihydroxy-4'-methoxyflavone as the main product. When anhydrous aluminum chloride was used in the demethylation of the acetate, the 5-tosyloxyl group was cleaved prior to the demethylation to give 5,6,7-trihydroxy-3,4'-dimethoxyflavone. Demethylation of 6-hydroxy-4',5,7-trimethoxy-3-(tosyloxy)flavone and its acetate with the bromide or chloride afforded the 5,6,7-trihydroxyflavone without the cleavage of the 3-tosyloxyl group, but was not suitable for the general synthesis of the 3,5,6,7-tetrahydroxyflavones because of the difficulty in removing the protecting group. Consequently, it was found that the direct demethylation of 3,6-dihydroxy-5,7-dimethoxyflavones with anhydrous aluminum chloride-sodium iodide in acetonitrile was the most useful general method for synthesizing 3,5,6,7-tetrahydroxyflavones. Additionally, the reported structures of two natural flavones were revised.