20197-48-2

Upstream product

• 18469-71-1 8-β-D-glucopyranosyl-5,7-dimethoxy-2-(4-methoxy-phenyl)-chromen-4-one 
• 2903-76-6 5,7-dihydroxy-2-(4-hydroxy-phenyl)-8-(tetra-O-acetyl-β-D-glucopyranosyl)-chromen-4-one 
• 119529-73-6 5,7,4'-Trimethoxy-8-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)flavanon 
• 186581-53-3 diazomethane 
• 108-24-7 acetic anhydride 
• 29702-25-8 isovitexin 
• 119529-70-3 8-bromo-4',5,7-trimethoxyflavanone 
• 3681-93-4 vitexin 
• 119529-71-4 8-(β-D-Glucopyranosyl)-5,7,4'-trimethoxyflavanon 
• 119529-69-0 8-bromo-4',5,7-trimethoxy-flavanone ethylene ketal 
• 119529-68-9 5,7,4'-Trimethoxyflavanon-ethylenacetal 
• 66074-95-1 4',5,7-trimethoxyflavanone 

Downstream Products

• 163395-88-8 5-hydroxy-7-methoxy-2-(4-methoxyphenyl)-8-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-4H-1-benzopyran-4-one 
• 20943-11-7 vitexin-4',7-di-O-methyl ether 

Relevant academic research and scientific papers

Glycosyl Imidates, 69. - Synthesis of Flavone C-Glycosides Vitexin, Isovitexin, and Isoembigenin

2-Hydroxy-4,6-dimethoxyacetophenone (4) was glycosylated with O-(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl) trichloroacetimidate (5) and trimethylsilyl triflate as promoter to yield directly the C-glycoside 6.Construction of the flavone system by application of a Baker-Venkataraman-type rearrangement followed by deprotection yielded isoembigenin (2).Glycosylation of 4,6-bis(tert-butyldimethylsilyloxy)-2-hydroxyacetophenone (17) with the trichloroacetimidate 5 afforded the O-glycoside intermediate 18 which was converted via Fries rearrangement into the C-glycoside 21.Applying again the Baker-Venkataraman rearrangement and cyclization gave isovitexin and vitexin derivatives 25 and 26, which were completely deprotected to yield isovitexin (1b) and vitexin (1a), respectively. - Key Words: Glycosides / Flavones / Vitexin / Isovitexin / Isoembigenin / Carbohydrates / Trichloroacetimidates / Fries rearrangement / Baker-Venkataraman rearrangement

Convenient Synthesis of C-β-D-Glucopyranosyl Arenes - Synthesis of 5,7,4'-Tri-O-methylvitexin

Reaction of the C-lithiated phenol and flavanon derivatives 4a-, b-A and 16-A with the ring-open, O-benzyl-protected D-glucoses 3 and 11 furnishes the corresponding C-glucosyl derivatives 5a,b, 12, and 19, respectively, in good yields.Hydrogenolytic deben