110-87-2

Basic information

• Product Name: 3,4-Dihydro-2H-pyran
• Synonyms: 3,4-Dihydro-2H-pyran,99%;2,3-Dihydro-2H-pyran;2,3-Dihydropyran, DHP;3,4-Dihydro-2H-pyran ,98%;3,4-Dihydro-2H-pyran (DHP);3,4-Dihydro-2H-pyran, 99% 100GR;3,4-Dihydro-2H-pyran, 99% 500GR;Dihydropyran,3,4-Dihydro-2H-pyran
• CAS NO: 110-87-2
• Molecular Formula: C₅H₈O
• Molecular Weight: 84.12
• EINECS: 203-810-4
• Product Categories: Protection and Derivatization;Halogenated Heterocycles ,Isoquinolines ,Quinolines ,Quinazolines ,Quinaldines;Oxygen cyclic compounds;Protection & Derivatization Reagents (for Synthesis);Synthetic Organic Chemistry;Others;Protecting and Derivatizing Reagents
• Mol File: 110-87-2.mol
• Article Data: 36

Chemical Properties

• Melting Point: −70 °C(lit.)
• Boiling Point: 86 °C(lit.)
• Flash Point: 4 °F
• Appearance: Clear colorless to yellow/Liquid
• Density: 0.922 g/mL at 25 °C(lit.)
• Vapor Density: 2.9 (vs air)
• Vapor Pressure: 74.4mmHg at 25°C
• Refractive Index: n20/D 1.440(lit.)
• Storage Temp.: Flammables area
• Solubility: 7.7g/l
• Explosive Limit: 1.1-13.8%(V)
• Water Solubility: 20 g/L (20 ºC)
• Stability: Volatile
• BRN: 103493
• CAS DataBase Reference: 3,4-Dihydro-2H-pyran(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-Dihydro-2H-pyran(110-87-2)
• EPA Substance Registry System: 3,4-Dihydro-2H-pyran(110-87-2)

Safety Data

• Hazard Codes: F,Xi
• Statements: 11-36/37/38-36/38-19
• Safety Statements: 16-26-36-37/39-33-7/9
• RIDADR: UN 2376 3/PG 2
• WGK Germany: 3
• RTECS: UP7700000
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 110-87-2(Hazardous Substances Data)

Usage

Description

3,4-Dihydro-2H-pyran is a colorless to light yellow liquid with unique chemical properties. It is a heterocyclic compound that plays a significant role in various chemical reactions and industries due to its ability to protect reactive functional groups and act as an intermediate in synthetic chemistry.

Uses

Used in Organic Synthesis:
3,4-Dihydro-2H-pyran is used as a hydroxyl-protecting reagent in organic synthesis. It serves to protect various reactive functional groups during chemical reactions, ensuring the desired product formation without unwanted side reactions.
Used in Polymer Industries:
In the polymer industry, 3,4-Dihydro-2H-pyran is involved in polymerization reactions, either alone or with unsaturated compounds. Its presence contributes to the development of polymers with specific properties and applications.
Used in the Preparation of Bicyclic Compounds:
3,4-Dihydro-2H-pyran is also employed in the synthesis of epoxide-fused bicyclic compounds, halo compounds, and allenic alcohols. These compounds find applications in various fields, including pharmaceuticals, materials science, and chemical research.
Overall, 3,4-Dihydro-2H-pyran is a versatile compound with a wide range of applications in different industries, primarily due to its ability to protect reactive functional groups and act as an intermediate in synthetic chemistry.

Flammability and Explosibility

Flammable

Safety Profile

A flammable and very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidzing materials. Keep away from heat and open flame. To fight fire, use alcohol foam, CO2, or dry chemical. When heated to decomposition it emits acrid smoke and irritating

Purification Methods

Partially dry dihydropyran with Na2CO3, then fractionally distil it. The fraction b 84-85o is refluxed with Na until hydrogen no longer evolves when fresh Na is added. It is then dried, and distilled again through a 60 x 1.2cm column packed with glass rings [Brandon et al. J Am Chem Soc 72 2120 1950, UV: Elington et al. J Chem Soc 2873 1952, NMR: Bushweller & O'Neil Tetrahedron Lett 4713 1969]. It has been characterised as the 3,5-dinitrobenzoyloxy-tetrahydrofuran derivative, m 103o which forms pale yellow crystals from dihydropyran/Et2O [Woods & Kramer J Am Chem Soc 69 2246 1947]. [Beilstein 17/1 V 181.]

InChI:InChI=1/C5H8O/c1-2-4-6-5-3-1/h2,4H,1,3,5H2

Upstream product

• 6559-34-8 6-methoxy-3,6-dihydro-2H-pyran 
• 926-62-5 isobutylmagnesium bromide 
• 920-39-8 isopropylmagnesium bromide 
• 109-99-9 tetrahydrofuran 
• 79322-55-7 tetrahydro-2-<(pent-3-ynyl)oxy>-2H-pyran 
• 6581-49-3 5-chloro-3,4-dihydro-2H-pyran 
• 6581-54-0 3-chlorotetrahydropyran 
• 7664-41-7 ammonia 
• 97-99-4 Tetrahydrofurfuryl alcohol 
• 109-92-2 ethyl vinyl ether 
• 94800-75-6 2-(2,4,6-Trimethyl-phenoxy)-tetrahydro-pyran 
• 108-95-2 phenol 
• 74-85-1 ethene 
• 107-02-8 acrolein 

Downstream Products

• 1720-37-2 2-(hex-5-yn-1-yloxy)tetrahydro-2H-pyran 
• 4875-14-3 2-(4-chloro-phenyl)-4a,6,7,8a-tetrahydro-5H-pyrano[3,2-e][1,3]thiazine-4-one 
• 20147-70-0 1-(4-nitro-phenyl)-(3ar,7ac)-1,3a,4,5,6,7a-hexahydro-pyrano[2,3-c]pyrazole-3-carboxylic acid ethyl ester 
• 5707-02-8 8-(toluene-4-sulfonyl)-(1rH,6cH)-2-oxa-7-thia-8-aza-bicyclo[4.2.0]octane 7c-oxide 
• 5707-02-8 8-(toluene-4-sulfonyl)-(1rH,6cH)-2-oxa-7-thia-8-aza-bicyclo[4.2.0]octane 7t-oxide 
• 33530-45-9 8-(toluene-4-sulfonyl)-2-oxa-7-thia-8-aza-bicyclo[4.2.0]octane 7-oxide 
• 88892-68-6 3-phenyl-3a,5,6,7a-tetrahydro-4H-pyrano<3,2-d>isoxazole 
• 18762-47-5 3-phenyl-(3ar,7ac)-3a,5,6,7a-tetrahydro-4H-pyrano[3,2-d]isoxazole 
• 66787-90-4 O⁴-(6-amino-2-benzyloxycarbonylamino-N⁶,O⁴-carbonyl-O³-(Ξ)-tetrahydropyran-2-yl-α-D-2,6-dideoxy-glucopyranosyl)-N³-benzyloxycarbonyl-N¹-((Ξ)-2-oxo-[1,3]oxazinane-6-carbonyl)-O⁶-(Ξ)-tetrahydropyran-2-yl-1D-2-deoxy-streptamine 
• 92577-08-7 8-(4-chloro-benzenesulfonyl)-2-oxa-8-aza-bicyclo[4.2.0]octan-7-one 
• 57492-52-1 4-benzyl-(5ar,9ac)-octahydro-pyrano[3,2-f][1,4]oxazepine 
• 57492-52-1 4-benzyl-(5ar,9at)-octahydro-pyrano[3,2-f][1,4]oxazepine 
• 68048-00-0 2-cyclohexyl-4ξ-ethyl-(4ar,8ac)-hexahydro-pyrano[3,2-e][1,2]oxazine-3ξ-carbonitrile 
• 59046-52-5 (3aR*,9aS,9bR*)-9b-ethoxycarbonyl-2,3,8,9,9a,9b-hexahydro-2,3-dioxo-1,4-diphenyl-1H-pyrano<2',3':6,5>pyrano<4,3-b>pyrrole 

Related news

Control of reactivity of novolac resins: the use of 3,4-Dihydro-2H-pyran (cas 110-87-2) as a labile protecting group08/26/2019

The control of the reactivity of novolac resins towards common crosslinkers through the use of 3,4-dihydro-2H-pyran as a protecting group is reported. This thermally labile protecting group is shown to be effective for the control of the cure of the novolac resin system through the use of models...detailed

3,4-Dihydro-2H-pyran (cas 110-87-2) promoted aerobic oxidative aromatization of 1,3,5-trisubstituted pyrazolines and Hantzsch 1,4-dihydropyridines08/25/2019

An unprecedented facile oxidation of 1,3,5-trisubstituted pyrazolines and Hantzsch 1,4-dihydropyridines (DHPs) to the corresponding pyrazoles and pyridines was observed, mediated by 3,4-dihydro-2H-pyran in air. The reaction showed excellent reactivity, functional group tolerance, and high yield ...detailed

Relevant articles and documents

Manganese-Catalyzed Desaturation of N-Acyl Amines and Ethers

Enamines and enol ethers are versatile synthons for chemical synthesis. While several methods have been developed to access such molecules, prefunctionalized starting materials are usually required, and direct desaturation methods remain rare. Herein, we report direct desaturation reactions of N-protected cyclic amines and cyclic ethers using a mild I(III) oxidant, PhI(OAc)2, and an electron-deficient manganese pentafluorophenylporphyrin catalyst, Mn(TPFPP)Cl. This system displays high efficiency for α,β-desaturation of various cyclic amines and ethers. Mechanistic probes suggest that the desaturation reaction occurs via an initial α-C-H hydroxylation pathway, which serves to protect the product from overoxidation.

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.

Stable vapor-phase conversion of tetrahydrofurfuryl alcohol into 3,4-2H-dihydropyran

Vapor-phase synthesis of 3,4-2H-dihydropyran (DHP) from tetrahydrofurfuryl alcohol (THFA) was investigated over acidic catalysts modified with transition metals. Catalytic activity of alumina was seriously deactivated in the reaction of THFA in nitrogen at 300 °C although the initial activity was high. Tetragonal ZrO2 showed the catalytic activity to produce DHP at 350 °C. Alumina modified with Cu exhibits stable catalytic activity with high selectivity to DHP under hydrogen flow conditions, and the optimum activity was obtained at CuO contents of 5-10 wt.%: the selectivity to DHP was as high as 85%. Prior to the reaction, CuO was reduced to metallic Cu, which probably works as a product remover together with hydrogen to prevent coke formation. The reaction pathway from THFA to DHP was discussed: it is speculated that THFA is initially rearranged into 2-hydroxytetrahydropyran, which rapidly dehydrated to DHP.

-

-

Production of 1,5-pentanediol via upgrading of tetrahydrofurfuryl alcohol

A method of making 1,5-pentanediol from tetrahydrofurfural alcohol. The method includes the steps of dehydrating tetrahydrofurfural alcohol (THFA) to dihydropyran (DHP); hydrating at least a portion of the DHP to 2-hydroxy-tetrahydropyran (2-HY-THP) in the presence of a solid acid catalyst; and hydrogenating at least a portion of the 2-HY-THP to 1,5-pentanediol. The method can be conducted entirely in the absence of noble metal catalysts.

PRODUCTION OF 1,5-PENTANEDIOL VIA UPGRADING OF TETRAHYDROFUFURYL ALCOHOL

A method of making 1,5-pentanediol from tetrahydrofurfural alcohol. The method includes the steps of dehydrating tetrahydrofurfural alcohol (THFA) to dihydropyran (DHP); hydrating at least a portion of the DHP to 2-hydroxy-tetrahydropyran (2-HY-THP) in the absence of homogeneous acid; and hydrogenating at least a portion of the 2-HY-THP to 1,5-pentanediol. The method can be conducted entirely in the absence of noble metal catalysts.