1920-21-4

Basic information

• Product Name: 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carbaldehyde
• Synonyms: 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carbaldehyde;2,5-Dimethyl-3,4-dihydro-2H-pyran-2-carbaldehyde;Methacrolein dimer;Methacrylaldehyde dimer
• CAS NO: 1920-21-4
• Molecular Formula: C₈H₁₂O₂
• Molecular Weight: 140.17968
• EINECS: 217-647-1
• Mol File: 1920-21-4.mol
• Article Data: 7

Chemical Properties

• Melting Point: -64.15°C
• Boiling Point: 196.69°C (rough estimate)
• Flash Point: 74.1°C
• Appearance: /
• Density: 1.0003 (rough estimate)
• Vapor Pressure: 0.308mmHg at 25°C
• Refractive Index: 1.4580 (estimate)
• CAS DataBase Reference: 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carbaldehyde(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carbaldehyde(1920-21-4)
• EPA Substance Registry System: 3,4-dihydro-2,5-dimethyl-2H-pyran-2-carbaldehyde(1920-21-4)

Safety Data

• Hazardous Substances Data: 1920-21-4(Hazardous Substances Data)

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 
• 107-25-5 methoxyethene 
• 50-00-0 formaldehyd 
• 123-38-6 propionaldehyde 
• 108-31-6 maleic anhydride 

Downstream Products

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

Relevant articles and documents

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.

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.

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.