51267-07-3

Upstream product

• 51267-06-2 (2,5-Dimethoxy-4-methyl-phenyl)-acetic acid methyl ester 
• 24599-58-4 2,5-dimethoxy toluene 
• 32378-21-5 2-(Chloromethyl)-5-methyl-1,4-dimethoxybenzene 
• 33121-14-1 4-(2,5-dimethoxy-4-methyl-benzylidene)-2-phenyl-4H-oxazol-5-one 
• 13321-74-9 1-bromo-2,5-dimethoxy-4-methylbenzene 
• 38439-76-8 2-(2,5-dimethoxy-4-methylphenyl)ethanol 

Downstream Products

• 29907-70-8 1-(2,5-Dimethoxy-4-methylphenyl)-2-propanon 
• 38844-23-4 1-(2,5-dimethoxy-4-methylphenyl)-2-propanol 
• 70318-70-6 2-(2',5'-dihydroxy-4'-methylphenyl)-acetic acid 
• 1276098-91-9 C₂₆H₂₅NO₅ 

Relevant academic research and scientific papers

Racemic and enantioselective total synthesis of heliespirones A & C

An account of the total synthesis of (±)-, (+)-heliespirone A and (±)-, (-)-heliespirone C is presented. In the first-generation total synthesis, we found rac-24a could be easily transformed to rac-heliespirones A & C in a biomimic way. Taking the disappointing diastereoselectivity of prenylation from 3 to 4, the nonselective dihydroxylation from 4 to 5 and the lenthy route in strategy A into account, we designed a different synthetic plan targeting a highly enantioselective, concise and protective-group free synthesis of heliespirones A & C. The palladium-catalyzed Michael addition and Sharpless AD played the key roles in the formation of optical lactone V, which could be easily transformed to compound I through two additional steps and the succedent operations were the same as those in the first-generation total synthesis. Our synthetic efforts indicated the bio-generation of heliespirones A & C from 24a should be a real process in nature.

Compositions based on direct dyestuffs containing a 2,5-dihydroxyphenylcarboxylic acid or a salt thereof

A composition suitable for dyeing keratin fibres, especially human hair, is provided comprising a direct dyestuff and, as a levelling agent, a 2,5-dihydroxyphenylcarboxylic acid or a salt thereof.