1920-21-4

Usage

Synthesis Reference(s)

Journal of the American Chemical Society, 72, p. 1531, 1950 DOI: 10.1021/ja01160a028

InChI:InChI=1/C8H12O2/c1-7-3-4-8(2,6-9)10-5-7/h5-6H,3-4H2,1-2H3

Upstream product

• 78-85-3 2-methylpropenal 
• 108-31-6 maleic anhydride 
• 107-25-5 methoxyethene 
• 50-00-0 formaldehyd 
• 123-38-6 propionaldehyde 

Downstream Products

• 54004-34-1 2,5-dimethyl-3,4-dihydro-2H-pyran-2-methanol 
• 13434-06-5 1,4-dimethyl-6,8-dioxa-bicyclo[3.2.1]octan-7-one 
• 72251-43-5 2,5-dimethyl-3,4-dihydro-2H-pyran-2-carbaldehyde phenylimine 
• 101654-49-3 2,5-dimethyl-3,4-dihydro-2H-pyran-2-carboxylic acid 
• 99115-09-0 5-hydroxy-2,5-dimethyl-tetrahydro-pyran-2-carbaldehyde 
• 6970-59-8 2-hydroxy-2,5-dimethyl-adipaldehyde 
• 78-85-3 2-methylpropenal 
• 104623-13-4 1,4-dimethyl-6,8-dioxa-bicyclo[3.2.1]octane-7-carboxylic acid 
• 10171-73-0 2,5-dimethyl-hexane-1,2,6-triol 
• 81115-73-3 2,5-dimethyl-3,4-dihydro-2H-pyran-2-carboxylic acid-(2,5-dimethyl-3,4-dihydro-2H-pyran-2-ylmethyl ester) 
• 93-53-8 (R)-2-phenylpropanal 
• 81115-72-2 (-)-2-phenylpropyl 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carboxylate 
• 81115-66-4 (S)-(-)-2-phenylpropyl (R)-(-)-2-phenylpropanoate 
• 81115-73-3 (-)-3,4-dihydro-2,2,5-trimethyl-2H-pyran 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carboxylate 

Relevant academic research and scientific papers

Racing carbon atoms. Atomic motion reaction coordinates and structural effects on Newtonian kinetic isotope effects

Intramolecular 13C kinetic isotope effects were determined for the dimerization of methacrolein. Trajectory studies accurately predict the isotope effects and support an origin in Newton's second law of motion, with no involvement of zero-point energy or transition state recrossing. Atomic motion reaction coordinate diagrams are introduced as a way to qualitatively understand the selectivity.

METHOD FOR PREPARING ISOBUTENOL

The present invention provides a method for manufacturing isobutenol comprising a step of selectively hydrogenating methacrolein in the presence of an additive. A manufacturing method according to the present invention can increase the selectivity of isobutenol. In the manufacturing method according to an exemplary embodiment of the present invention, the additive represented by the chemical formula 1 is added to provide isobutenol with high selectivity, and the selective hydrogenation reaction is predominant, so that the amount of a catalyst can be reduced.

OPTIMIZED METHOD FOR PRODUCING METHACROLEIN

The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavourings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

Substituents influences on the rate of α-alkylacroleins dimerization

Kinetics of α-alkylacroleins dimerization was studied. It was established that both electronic and steric factors affect the process rate, with the prevalence of the latter factors.

Synthesis and biological activity of α-alkylacrolein dimers and their derivatives

Dimers of methacrolein and α-ethylacrolein have been obtained and undergo a Cannizzaro reaction to the corresponding pyran alcohols and sodium salts of pyran acids. Their bacteriostatic, bactericidal, and fungicidal properties have been studied.

Anomeric effect enhancement in C-5-substituted 2-methoxytetrahydropyrans

cis- and trans-2.5-Dimethoxytetrahydropyrans, cis-2,5-dimethoxy-6-methyltetrahydropyran and 2-methoxy-5-methyltetrahydropyran have been examined to see the effect of an OCH3 group at position 5 on the degree of anomeric effect in substituted 2-methoxytetrahydropyrans. The present study shows that this group stabilises the C-2 electronegative substituent in the axial position. Semi-empirical and ab initio molecular orbital calculations support this view, AM1 calculation gives lower enthalpies as well as lower dipole moments for the compounds having an OCH3 group in the axial position at C-2 over the equatorial form in 2-methoxytetrahydropyrans. This enhanced stabilisation is attributed to the electrostatic interaction between the partial positive charge at C-5 and the partial negative charge of the aglycone oxygen atom.

Aqueous catalysis: Methylrhenium trioxide (MTO) as a homogeneous catalyst for the Diels-Alder reaction

The title compound proves to be an effective and efficient catalyst for the Diels-Alder reaction when the dienophile is an α,β-unsaturated ketone or aldehyde. It is especially effective in water. Equal amounts of any such dienophile and any of six representative dienes (isoprene, 2-methyl-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, cyclopentadiene, 1,2,3,4,5-pentamethylcyclopentadiene, and 1,3-cyclohexadiene) were used, along with 1% MTO. The reactions gave usually > 90% isolated yield of the cycloaddition product except for the larger dienophiles. Nearly exclusively, there was formed one product isomer, the same one that usually predominates. The reactions were often run in chloroform (mostly) and in other organic solvents. A select number were carried out in water, where the reactions gave a greater product yield in a considerably shorter time. Water, itself, is known to enhance the rates of Diels-Alder reactions, but MTO exerts an additional accelerating effect. Kinetics studies were carried out to show that the rate is proportional to the catalyst concentration. The products do not inhibit the reaction. The desirability of MTO as a Diels-Alder catalyst stems from a combination of favorable properties: the inertness to air/oxygen, the tolerance for many substrates, the use of an aqueous medium, and the absence of product inhibition. The initial step appears to be the (weak) coordination of the carbonyl oxygen to the electropositive rhenium center. Steric crowding around rhenium inhibits reactions of the larger dienophiles.