74161-28-7

Upstream product

• 188927-60-8 7-Benzyloxy-2-(3-benzyloxy-4-methoxy-phenyl)-3,5-dihydroxy-6-methoxy-chromen-4-one 
• 3162-51-4 1-(2,4-Bis-benzyloxy-3,6-dimethoxy-phenyl)-ethanone 
• 3162-52-5 1-(4-benzyloxy-2-hydroxy-3,6-dimethoxy-phenyl)-ethanone 
• 7499-99-2 1-(2,4-dihydroxy-3,6-dimethoxy)phenylethanone 
• 188927-31-3 4-benzyloxy-6-hydroxy-3-methoxy-2-isopropoxyacetophenone 
• 188927-55-1 Toluene-4-sulfonic acid 7-benzyloxy-2-(3-benzyloxy-4-methoxy-phenyl)-5-isopropoxy-6-methoxy-4-oxo-4H-chromen-3-yl ester 
• 188927-45-9 Toluene-4-sulfonic acid 7-benzyloxy-2-(3-benzyloxy-4-methoxy-phenyl)-5-hydroxy-6-methoxy-4-oxo-4H-chromen-3-yl ester 
• 188927-40-4 7-Benzyloxy-2-(3-benzyloxy-4-methoxy-phenyl)-3-hydroxy-5-isopropoxy-6-methoxy-chromen-4-one 
• 188927-35-7 1-(4-Benzyloxy-6-hydroxy-2-isopropoxy-3-methoxy-phenyl)-3-(3-benzyloxy-4-methoxy-phenyl)-propane-1,3-dione 
• 188927-50-6 7-Benzyloxy-2-(3-benzyloxy-4-methoxy-phenyl)-5-isopropoxy-6-methoxy-chromen-4-one 
• 188927-62-0 1-(4-Benzyloxy-2-isopropoxy-3,6-dimethoxy-phenyl)-ethanone 

Relevant academic research and scientific papers

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

The demethylation of 3,4-dioxygenated 6-methoxy-2- isopropoxyacetophenones was studied and it was found that 4-benzyloxy-6- hydroxy-3-methoxy-2-isopropoxyacetophenone was easily obtained from 4- benzyloxy-3,6-dimethoxy-2-isopropoxyacetophenone by selective demethylation with anhydrous aluminum bromide-sodium iodide in acetonitrile. The acetophenone was converted into 7-benzyloxy-3-hydroxy-6-methoxy-5- isopropoxyflavones by cyclization followed by oxidation with dimethyldioxirane. The isopropoxy group in the flavones was selectively cleaved with anhydrous aluminum chloride via the corresponding tosylates to give 7-benzyloxy-3,5-dihydroxy-6-methoxyflavones, which were converted into the desired 3,5,7-trihydroxy-6-methoxyflavones by hydrogenolysis. The process was suitable as a general method for synthesizing 3,5,7-trihydroxy-6- methoxyflavones and five flavones were synthesized. We also examined the 13C-NMR spectra of twelve kinds of 3,5,6,7-tetraoxygenated 4'- methoxyflavones and revised the proposed structure of a natural flavone.