2270-61-3

Basic information

• Product Name: 3,4-dihydro-4-methyl-2H-pyran
• Synonyms: 3,4-dihydro-4-methyl-2H-pyran
• CAS NO: 2270-61-3
• Molecular Formula: C₆H₁₀O
• Molecular Weight: 98.143
• EINECS: 218-875-4
• Mol File: 2270-61-3.mol

Chemical Properties

• Boiling Point: 117.5°Cat760mmHg
• Flash Point: 17.3°C
• Appearance: /
• Density: 0.885g/cm³
• Vapor Pressure: 20.7mmHg at 25°C
• Refractive Index: 1.436
• CAS DataBase Reference: 3,4-dihydro-4-methyl-2H-pyran(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-dihydro-4-methyl-2H-pyran(2270-61-3)
• EPA Substance Registry System: 3,4-dihydro-4-methyl-2H-pyran(2270-61-3)

Safety Data

• Hazardous Substances Data: 2270-61-3(Hazardous Substances Data)

Usage

InChI:InChI=1/C6H10O/c1-6-2-4-7-5-3-6/h2,4,6H,3,5H2,1H3

Upstream product

• 7429-33-6 2-Butoxy-3,4,5,6-tetrahydro-4-methyl-2H-pyran 
• 25724-34-9 4-methyl-2-ethoxytetrahydropyran 
• 16302-35-5 4-methyl-3,6-dihydro-2H-pyran 
• 36838-71-8 4-methylene-tetrahydro-pyran 
• 6559-34-8 6-methoxy-3,6-dihydro-2H-pyran 
• 75-16-1 methylmagnesium bromide 
• 50-00-0 formaldehyd 
• 115-11-7 isobutene 
• 18653-57-1 4-Methyl-3,4,5,6-tetrahydro-2H-pyran-2-ol 
• 4166-53-4 3-methylglutaric anhydride 
• 1121-84-2 4-methyl-tetrahydro-pyran-2-one 
• 790661-89-1 trifluoromethanesulfonic acid 4-methyl-5,6-dihydro-4H-pyran-2-yl ester 
• 331-58-8 2-Butoxy-3,4-dihydro-4-methyl-2H-pyran 

Downstream Products

• 103905-02-8 Acetic acid (2E,6E)-9-benzenesulfonyl-3,7-dimethyl-8-(4-methyl-tetrahydro-pyran-2-yloxy)-9-(2,6,6-trimethyl-cyclohex-1-enyl)-nona-2,6-dienyl ester 
• 57745-77-4 2-(2,4-Dichlorphenoxy)-3,4,5,6-tetrahydro-4-methyl-2H-pyran 
• 7429-34-7 trans-2-hydroxy-4-methyltetrahydropyran 
• 7429-34-7 cis-2-hydroxy-4-methyltetrahydropyran 
• 1679-47-6 3-methyltetrahydro-2-furanone 
• 906716-81-2 4-methyl-2-(thiophenyl)tetrahydropyran 
• 119232-78-9 (5E,9E)-5,9,11-Trimethyl-13-(toluene-4-sulfonyl)-trideca-5,9-dien-2-ol 
• 119232-77-8 (4E,8E)-4,8,10-Trimethyl-12-(toluene-4-sulfonyl)-dodeca-4,8-dienal 
• 119232-76-7 (4E,8E)-4,8,10-Trimethyl-12-(toluene-4-sulfonyl)-dodeca-4,8-dien-1-ol 

Relevant articles and documents

Isoprene synthesis from formaldehyde and isobutene over Keggin-type heteropolyacids supported on silica

Gas phase Prins condensation of isobutene with formaldehyde has been studied over different Keggin-type heteropolyacids supported on amorphous silica. The catalysts were characterized by elemental analysis, X-ray diffraction, low temperature nitrogen adsorption, TPD of ammonia, FTIR of adsorbed pyridine and NMR spectroscopy. The activity of the supported heteropoly compounds was found to increase in the following order: H4SiMo12O40 3PMo12O40 4SiW12O40 ≈ H3PW12O40. The lower activity of the supported molybdenum heteropolyacids was attributed to their low thermal stability and partial decomposition during catalyst activation, which resulted in lower acidity. The variation of HPA content from 5 to 33 wt% was also shown to increase catalyst activity. Based on the relationship between the content of weak Br?nsted sites, the amount and type of carbonaceous deposits and the catalytic activity, it was concluded that the generation of working active sites over HPA catalysts involves the formation of unsaturated branched surface species over weak Br?nsted sites. These active carbonaceous species are responsible for selective isoprene synthesis. The best catalyst performance is observed over the catalyst with 20 wt% of H3PW12O40, which shows an isoprene yield of 48% with a selectivity of 63%.

METHOD OF PRODUCING 4-METHYL-3,4-DIHYDRO-2H-PYRAN

PROBLEM TO BE SOLVED: To provide a method of obtaining 4-methyl-3,4-dihydro-2H-pyran industrially, inexpensively, and at a high purity. SOLUTION: A method of producing 4-methyl-3,4-dihydro-2H-pyran comprises a step (1) of dewatering 2-hydroxy-4-methyl tetrahydropyran in the presence of acid and/or acid salt. COPYRIGHT: (C)2015,JPOandINPIT

Synthesis of isoprene from formaldehyde and isobutene over phosphate catalysts

Vapor phase Prins condensation of isobutene with formaldehyde has been studied over boron (BP), aluminum (AlP), titanium (TiP), zirconium (ZrP) and niobium (NbP) phosphates. The catalysts were characterized by elemental analysis, X-ray diffraction, low-te

A synthesis of 6-tributylstannyl-3,4-dihydro-2H-pyrans via coupling of enol triflates with (Bu3Sn)(Bu)Culi·liCN

Enol triflates derived from 6- and 7-membered ring lactones (6 cases) react with (Bu3Sn)(Bu)CuLi·LiCN in THF at -78 °C to give the corresponding α-tributylstannyl cyclic enol ethers in 54-85% yield.

Regioselective Ni(II)-assisted alkylation of 2-methoxy-5,6- dihydro-2H-pyran: A new route to 2-n.alkyl-5,6-dihydro-2H-pyrans

In the presence of a catalytic amount of NidppeCl2, 2-methoxy- 5,6-dihydro-2H-pyran reacts with primary Grignard reagents to give the corresponding 2-n.alkyl-5,6-dihydro-2H-pyrans in satisfactory yields.

EXPERIMENTAL STUDIES OF THE ANOMERIC EFFECT. PART I. 2-SUBSTITUTED TETRAHYDROPYRANS.

Variable temperature (1)H and (13)C n.m.r. studies in CFCl3/CDCl3 of equilibria in 2-substituted- and 2-substituted-4-methyl-tetrahydropyranes have given conformational enthalpy differences and conformational entropy differences for chloro, methoxy, hydroxy and methylamino substituents.For ΔHoa->e, the values obtained, in kcal /mol, were 1.67 (Cl), 0.03 (OCH3), -0.63 (OH) and -1.75 (NHCH3); for ΔSoa->e the values obtained, in cal K-1mol-1 were -1.69 (Cl), -2.52 (OCH3), -2.50 (OH) and -0.60 (NHCH3).The trend in ΔHo values confirms the importance of antiperiplanar n-?* stabilisation as a contributor to the explanation of the anomeric effect, and supports a suggestion that endo- and exo-anomeric effects which occur in the same conformation are competitive.A variable temperature (13)C n.m.r. study of (Me-(13)C)-4-methyl-tetrahydropyran in CD2Cl2 has given a conformational enthalpy difference (ΔHoa->e) of -1.86 kcal/mol and a conformational entropy difference (ΔSoa->e) of -0.07 cal K-1mol-1 for a methyl substituent at the 4-position of a tetrahydropyran.

REACTIONS INVOLVING SHIFTING OF THE DOUBLE BOND IN CYCLIC ETHERS

4-Methylenetetrahydropyran undergoes isomerization to 4-methyl-5,6-dihydropyran in the presence of sodium on aluminum oxide.Both pyrans are converted to a vinyl ether, viz., 4-methyl-2,3-dihydropyran, under the influence of iron pentacarbonyl.