74628-36-7

Upstream product

• 74628-35-6 2',6,6'-trimethoxy-4-methylspiro-3(2H),4'-dione 
• 55366-03-5 methyl 2-bromo-4-methoxy-6-methylbenzoate 
• 20491-92-3 2,4,6-trimethoxyphenol 
• 830-79-5 2,4,6-trimethoxybenzaldehyde 
• 621-23-8 1,2,3-trimethoxybenzene 
• 81574-60-9 methyl 4-methoxy-2-(2,4,6-trimethoxyphenoxy)-6-methylbenzoate 
• 81574-62-1 methyl 2-(4-hydroxy-2,6-dimethoxyphenoxy)-4-methoxy-6-methylbenzoate 

Downstream Products

• 15222-53-4 lichenxanthone 
• 15222-54-5 1,3,6-trimethoxy-8-methyl-9H-xanthen-9-one 
• 81574-62-1 methyl 2-(4-hydroxy-2,6-dimethoxyphenoxy)-4-methoxy-6-methylbenzoate 
• 81574-60-9 methyl 4-methoxy-2-(2,4,6-trimethoxyphenoxy)-6-methylbenzoate 
• 74628-37-8 2-hydroxy-2',4,4'6'-tetramethoxy-6-methylbenzophenone 

Relevant academic research and scientific papers

Depsidone Synthesis. Part 21. A New Synthesis of Grisa-2',5'-diene-3,4'-diones

Treatment of suitably substituted methyl 2-phenoxybenzoates with titanium(IV) chloride and dry hydrogen chloride afforded grisa-2',5'-diene-3,4'-diones in high yield.The structures of these compounds followed from their thermal stability, their methanolysis to methyl 2-(4-hydroxyphenoxy)benzoates, and their reductive cleavage to 2,4'-dihydrobenzophenones.Treatment of the benzophenones with base gave xanthones.An attempt to synthesize dehydrogriseofulvin (1) by this method failed.

Synthesis of Grisa-2',5'-dien-3,4'-diones by Intramolecular ipso-Substitution

Appropriately substituted o-phenoxybenzoic esters on treatment with dry hydrogen chloride and titanium(IV) chloride in dichloromethane yield grisa-2',5'-dien-3,4'-diones by intramolecular ipso-substitution.