84346-76-9

Upstream product

• 541-47-9 3-Methylbutenoic acid 
• 150-76-5 4-methoxy-phenol 
• 57539-84-1 1,3-Dichloro-3-methyl-2-butanone 
• 34876-10-3 3-methyl-2-butenoic anhydride 
• 1318766-85-6 C₂₁H₁₈N₂O₈ 
• 38614-36-7 2-methylpropen-1-ylmagnesium bromide 
• 7693-41-6 4-methoxyphenylchloroformate 
• 3350-78-5 3,3-Dimethylacryloyl chloride 

Downstream Products

• 13229-59-9 6-methoxy-2,2-dimethylchroman-4-one 
• 29423-73-2 3,4-dihydro-6-methoxy-4,4-dimethyl-2H-1-benzopyran-2-one 
• 4394-72-3 4-methyl-6-(2-methylprop-1-en-1-yl)-2H-pyran-2-one 
• 150-76-5 4-methoxy-phenol 
• 98910-62-4 7-hydroxy-4-methoxy-3,3-dimethylindanone 
• 84346-78-1 1-(2-hydroxy-5-methoxyphenyl)-3-methylbut-2-en-1-one 
• 29423-72-1 3,4-dihydro-6-hydroxy-4,4-dimethyl-2H-1-benzopyran-2-one 
• 123-31-9 hydroquinone 
• 22927-97-5 6-methoxy-2,2-dimethyl-2H-chromene 

Relevant academic research and scientific papers

Expeditious photochemical reaction toward the preparation of substituted chroman-4-ones

A facile photochemical preparation of 5-, 6-, and 7-substituted chroman-4-ones from aryl 3-methyl-2-butenoate esters is described. The two-phase base-catalyzed method relies upon two consecutive processes in one-pot reaction through a photo-Fries rearrangement and a based-catalyzed intramolecular oxa-Michael addition to afford the desired products.

Widely useful DMAP-catalyzed esterification under auxiliary base- and solvent-free conditions

With regard to atom economy and E-factor, catalytic condensation of carboxylic acids with equimolar amounts of alcohols is the most desirable. Although several highly active dehydration catalysts have been reported, more efficient alternatives are still strongly needed because the dehydrative esterification of tertiary alcohols, phenols, acid-sensitive alcohols, amino acids, and hardly soluble alcohols has never proceeded satisfactorily. Here we report new insights into the classical DMAP-catalyzed acylation of alcohols: surprisingly, only a 0.05-2 mol % of DMAP can efficiently promote acylation of alcohols with acid anhydrides under auxiliary base- and solvent-free conditions to give the corresponding esters in high yields. Furthermore, we achieved the recovery and reuse of commercially available polystyrene-supported DMAP without using any solvents. These serendipitous findings provide widely useful and environmentally benign esterification methods, which might be more practical and reliable than catalytic dehydrative condensation methods, in particular, for the less reactive alcohols which hardly condense with carboxylic acid directly.

Reactivity of α,α′-dichloroketones towards anions electrogenerated at carbonium and oxygen atoms. Electrochemically-induced Favorskii rearrangement. Part 2

Electrolyses of solutions containing α,α′-dichloroketones 1a or 2a were carried out, on a mercury pool or glassy carbon cathode, at a potential sufficiently negative to allow two-electron cleavage of the C-Cl bond. The effects of the presence of carboxylic acids 3a,b, phenols 4a-f, or carbon acid 5 in the solutions were evaluated. Depending on the type of acidic substrate, it was possible to isolate from the cathodic solutions the Favorskii-rearrangement products 9m, 10m, 11 and 12, as well as dechlorinated ketones 1b and 2b and the addition products 7m and 8m. The conditions under which it was possible, by electrochemical means, to induce the Favorskii rearrangement between dichloroketones 1a and 2a and the acidic substrates are discussed. Evidence was gained by voltammetric analysis that the rates of formation of the Favorskii adducts 9a-f depend on the structures of the corresponding phenols 4a-f. By employing electrogenerated bases, it was possible to obtain α,β-unsaturated ketones at potentials less negative than required for the direct reduction of 1a and 2a. Elsevier.

ON THE REACTION OF SUBSTITUTED PHENOLS AND 3-METHYLBUT-2-ENOIC ACID. A COMPARATIVE STUDY

A systematic and comparative study of the reaction of a series of substituted phenols and 3-methylbut-2-enoic acid in zinc chloride/phosphorus oxychloride and aluminum chloride/phosphorus oxychloride reveals that the formation of phenolic esters and 2,2-dimethyl-4-chromanones is strongly influenced by the substituents, their popsition on the aromatic ring of the starting phenols.Based on our study, a mixed Friedel-Crafts and Fries rearrangement mechanism is in operation in these reactions.

On the synthesis of substituted 2,2-dimethyl1-4-chromanones and related compounds

A systematic study of the reaction of a series of monosubstituted phenols 3 and 3-methylbut-2-enoic acid 4 in phosphorus oxychloride/zinc chloride revealed that the formation of 4-chromanones was strongly infuenced by the substituents and their position on the aromatic ring of the starting phenols.