764-13-6

Basic information

• Product Name: 2,5-Dimethyl-2,4-hexadiene
• Synonyms: (CH3)2C=CHCH=C(CH3)2;2,5-dimethyl-4-hexadiene;1,1,4,4-TetraMethylbuta-1,3-diene;NSC 10812;DiMethyl-2,4-hexa;2,5-Dimethyl-2,4-Hexadiene in china;2,5-Dimethyl-2,4-hexadiene 96%;4-Hexadiene,2,5-dimethyl-2
• CAS NO: 764-13-6
• Molecular Formula: C₈H₁₄
• Molecular Weight: 110.2
• EINECS: 212-115-5
• Product Categories: Pharmaceuticals;Acyclic;Alkenes;Organic Building Blocks;Aliphatics;Intermediates & Fine Chemicals;Mutagenesis Research Chemicals
• Mol File: 764-13-6.mol
• Article Data: 26

Chemical Properties

• Melting Point: 12 °C
• Boiling Point: 132134°C
• Flash Point: 85 °F
• Appearance: clear colourless liquid
• Density: 0.773 g/mL at 25 °C(lit.)
• Vapor Density: 3.8 (vs air)
• Vapor Pressure: 26.9 mm Hg ( 37.7 °C)
• Refractive Index: n20/D 1.476(lit.)
• Storage Temp.: Flammables area
• Solubility: Chloroform, Ethyl Acetate
• BRN: 1733342
• CAS DataBase Reference: 2,5-Dimethyl-2,4-hexadiene(CAS DataBase Reference)
• NIST Chemistry Reference: 2,5-Dimethyl-2,4-hexadiene(764-13-6)
• EPA Substance Registry System: 2,5-Dimethyl-2,4-hexadiene(764-13-6)

Safety Data

• Hazard Codes: Xi,Xn
• Statements: 10-36/37/38-20/21/22
• Safety Statements: 16-26-36-36/37/39
• RIDADR: UN 3295 3/PG 3
• WGK Germany: 3
• TSCA: Yes
• HazardClass: 3
• PackingGroup: III
• Hazardous Substances Data: 764-13-6(Hazardous Substances Data)

Usage

Chemical Properties

clear colourless liquid

Uses

Different sources of media describe the Uses of 764-13-6 differently. You can refer to the following data:
1. 2,5-dimethyl-2,4-hexadiene is a volatile alkyl compound present in tobacco smoke. It is used as a potential biomarker in breath for prediction of lung cancer.
2. 2,5-Dimethyl-2,4-hexadiene may be used in the synthesis of (+)-trans-(1R,3R)-chrysanthemic acid methyl ester.

General Description

2,5-Dimethyl-2,4-hexadiene is an electron-rich alkene. It induces photodechlorination of 9,10-dichloroanthracene and its mechanism has been investigated. Asymmetric cyclopropanation of 2,5-dimethyl-2,4-hexadiene with tert-butyl diazoacetate catalyzed by the new copper-bisoxazoline complex has been reported. 2,5-Dimethyl-2,4-hexadiene has been investigated as a singlet oxygen acceptor in various solvents. Mechanism of addition reaction of aromatic and aliphatic thiols with 2,5-dimethyl-2,4-hexadiene has been investigated.

Purification Methods

Distil, then repeatedly fractionally crystallise it by partial freezing. Immediately before use, the diene is passed through a column containing Woelm silica gel (activity I) and Woelm alumina (neutral) in separate layers. [Beilstein 1 IV 1043.]

InChI:InChI=1/C8H14/c1-3-5-7-8-6-4-2/h3-6H,7-8H2,1-2H3/b5-3-,6-4-

Synthetic route

6-acetoxy-1-cyclohexene-1-carbonitrile (130251-99-9) + Me2C=CHMgX → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 6-(2-methylprop-1-enyl)-1-cyclohexene-1-carbonitrile

Conditions	Yield
Stage #1: Me2C=CHMgX With indium(III) chloride In tetrahydrofuran at 20℃; for 1h; Stage #2: 6-acetoxy-1-cyclohexene-1-carbonitrile With triphenylphosphine; tris-(dibenzylideneacetone)dipalladium(0) In tetrahydrofuran	A n/a B 89%

(Z)-2,5-dimethyl-2,5-dihydroxy-3-hexene monomethyl ether (84072-34-4) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With lithium aluminium tetrahydride; titanium(III) chloride In tetrahydrofuran for 3h; Heating;	82%

2,4-diisopropyl-6,6-dimethyl-1,3-dioxane (1403460-42-3) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
tricalcium diphosphate at 400℃;	80%

trans-2,5-dimethyl-3-hexene-2,5-diol (927-81-1) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With lithium aluminium tetrahydride; titanium(III) chloride In tetrahydrofuran for 3h; Heating;	78%

2,2,4-trimethyl-3-pentanal p-tozylhydrazonate (42302-74-9) → (E)-2,4-dimethyl-hexa-2,4-diene (82937-01-7) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 2-(2,2-dimethyl-cyclopropyl)-2-propene (1121-35-3) + 1-(1-methylcyclopropyl)-2-methyl-1-propene (42302-76-1)

Conditions	Yield
In diethylene glycol dimethyl ether at 160℃; Further byproducts given;	A 1.2% B 75.3% C 1.1% D 19%

2,2,4-trimethyl-3-pentanal p-tozylhydrazonate (42302-74-9) → (E)-2,4-dimethyl-hexa-2,4-diene (82937-01-7) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 1-(1-methylcyclopropyl)-2-methyl-1-propene (42302-76-1) + (Z)-2,4-Dimethyl-2,4-hexadiene (82937-00-6)

Conditions	Yield
In diethylene glycol dimethyl ether at 160℃; Further byproducts given;	A 1.2% B 75.3% C 19% D 0.6%

2-methyl-1-propenylbromide (3017-69-4) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With dibromobis(triphenylphosphine)nickel(II); triphenylphosphine; zinc In acetonitrile at 20℃; for 6h;	75%
With potassium iodide; nickel dichloride; zinc In N,N,N,N,N,N-hexamethylphosphoric triamide at 40℃; for 9h;	74%
With diethyl ether; sodium

3,4-dilithio-2,5-dimethyl-2,4-hexadiene (96445-43-1) + acetophenone (98-86-2) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3-isopropylidene-5-methyl-2-phenyl-hex-4-en-2-ol + 3,3,6,6-tetramethyl-2,7-diphenyl-4-octyn-2,7-diol

Conditions	Yield
In diethyl ether at -60℃; Condensation; hydrolysis;	A 20% B 10% C 70%

3,4-dilithio-2,5-dimethyl-2,4-hexadiene (96445-43-1) + acetone (67-64-1) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3-isopropylidene-2,5-dimethyl-4-hexen-2-ol (30762-44-8) + 2,3,3,6,6,7-hexamethyl-4-octyn-2,7-diol

Conditions	Yield
In diethyl ether at -40℃; Condensation; hydrolysis;	A 10% B 70% C 20%

(Z)-1-bromo-1-nonene (39924-58-8) + 2-methylpropen-1-ylmagnesium bromide (38614-36-7) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + (Z)-2-methyl-2,4-dodecadiene (188430-61-7) + octadeca-8,10-diene (107678-80-8, 108035-62-7) + (E)-2-methyl-2,4-dodecadiene

Conditions	Yield
Stage #1: (Z)-1-bromonon-1-ene With magnesium In tetrahydrofuran; ethylene dibromide at 5 - 20℃; Inert atmosphere; Stage #2: 2-methylpropen-1-ylmagnesium bromide With oxygen; lithium chloride; manganese(ll) chloride In tetrahydrofuran at -60℃; Inert atmosphere; optical yield given as %de;	A 70% B n/a C 15% D n/a

(Z)-2,5-dimethyl-2,5-dihydroxy-3-hexene dimethyl ether (84072-35-5) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With lithium aluminium tetrahydride; titanium(III) chloride In tetrahydrofuran for 3h; Heating;	64%

3,4-dilithio-2,5-dimethyl-2,4-hexadiene (96445-43-1) + acetaldehyde (75-07-0) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 5-methyl-3-isopropylidene-4-hexen-2-ol + 3,3,6,6-tetramethyl-4-octyn-2,7-diol

Conditions	Yield
In diethyl ether at -60℃; Condensation; hydrolysis;	A 20% B 33% C 47%

3,4-dilithio-2,5-dimethyl-2,4-hexadiene (96445-43-1) + acetone (67-64-1) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3-isopropylidene-2,5-dimethyl-4-hexen-2-ol (30762-44-8) + 2,3,3,6,6,7-hexamethyl-4-octyn-2,7-diol + 3-(2-methyl-1-propenylidene)-2,4,4,5-tetramethylhexan-2,5-diol

Conditions	Yield
In N,N,N,N,N,N-hexamethylphosphoric triamide; diethyl ether at -80℃; Condensation; hydrolysis;	A 5% B 28% C 34% D 33%

2,2,4,4-tetramethyl-6-oxabicyclo<3.1.0>hexan-3-one (97455-13-5) → dimethylketene (598-26-5) + 2,2-dimethyl-3-(2,2-dimethyl-vinyl)-oxirane (13295-59-5) + 2,5-dimethyl-hex-4-en-3-one (13905-13-0) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3,3-dimethyl acrylaldehyde (107-86-8) + Bis(2-methylprop-1-enyl) ether (764-51-2)

Conditions	Yield
In pentane Mechanism; Irradiation;	A 10% B 15% C 4% D 19% E 26% F 26%
In pentane at 0℃; for 2h; Irradiation; n-ϖ* excitation is dicsussed in terms of Salem diagrams;

2,2,4,4-tetramethyl-6-oxabicyclo<3.1.0>hexan-3-one (97455-13-5) → dimethylketene (598-26-5) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3,3-dimethyl acrylaldehyde (107-86-8) + Bis(2-methylprop-1-enyl) ether (764-51-2)

Conditions	Yield
In pentane Irradiation; Further byproducts given;	A 10% B 19% C 26% D 26%

2,2,4,4-tetramethyl-6-oxabicyclo<3.1.0>hexan-3-one (97455-13-5) → 2,2-dimethyl-3-(2,2-dimethyl-vinyl)-oxirane (13295-59-5) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3,3-dimethyl acrylaldehyde (107-86-8) + Bis(2-methylprop-1-enyl) ether (764-51-2)

Conditions	Yield
In pentane Irradiation; Further byproducts given;	A 15% B 19% C 26% D 26%

2,2,4,4-tetramethyl-6-oxabicyclo<3.1.0>hexan-3-one (97455-13-5) → 2,5-dimethyl-hex-4-en-3-one (13905-13-0) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3,3-dimethyl acrylaldehyde (107-86-8) + Bis(2-methylprop-1-enyl) ether (764-51-2)

Conditions	Yield
In pentane Irradiation; Further byproducts given;	A 4% B 19% C 26% D 26%

terephthalonitrile (623-26-7) + methanol (67-56-1) + 2,5-dimethyl-1,4-hexadiene (927-97-9) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 4-(4-cyanophenyl)-5-methoxy-2,5-dimethyl-1-hexene + 5-(4-cyanophenyl)-4-methoxy-2,5-dimethyl-1-hexene

Conditions	Yield
With biphenyl In acetonitrile at 10℃; for 26h; Irradiation;	A 3% B 9% C 16%

2,5-dimethyl-2,5-hexanediol (110-03-2) + aniline hydrobromide (542-11-0) → 2,2,5,5-tetramethyltetrahydrofuran (15045-43-9) + 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
beim Destillieren;

2,5-dimethyl-2,5-hexanediol (110-03-2) → 2,5-dimethyl-1,5-hexadiene (627-58-7) + 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With pumice stone; zirconium(IV) oxide at 300℃;

2,5-dimethyl-2,5-hexanediol (110-03-2) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With aluminum oxide; phosphoric acid at 250℃;
With chromium corundum at 350℃;
Multi-step reaction with 2 steps 1: glacial acetic acid; hydrogen chloride / und nachfolgenden Aufbewahren 2: soda lime / 255 - 270 °C / 12 - 20 Torr View Scheme

2,5-dimethyl-1,5-hexadiene (627-58-7) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With toluene-4-sulfonic acid
With calcium amide
With aluminum oxide

1,1,2-tribromo-2-methyl-propane (15331-16-5) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With diethyl ether; magnesium

2,5-dichloro-2,5-dimethyl hexane (6223-78-5) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With soda lime at 255 - 270℃; under 12 - 20 Torr;

2,5-Dimethyl-4-hexen-3-ol (60703-31-3) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 2,5-dimethyl-hexa-2,3-diene (36721-80-9)

Conditions	Yield
With aluminum oxide

2,5-dichloro-2,5-dimethyl-3-hexyne (2431-30-3) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 2,5-dimethyl-hexa-2,3-diene (36721-80-9)

Conditions	Yield
With lithium aluminium tetrahydride; diethyl ether

2,5-dimethyl-1,5-hexadiene (627-58-7) + toluene-4-sulfonic acid (104-15-4) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
Isomerisierung;

2-methylprop-1-enyllithium (29917-94-0) + dimethylglyoxal (431-03-8) → meso-2,4,5,7-tetramethyl-2,4-octadiene-4,5-diol (105906-21-6) + 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With diethyl ether

2,5-dimethyl-4-hexen-2-ol (14908-27-1) → 2,5-Dimethyl-2,4-hexadiene (764-13-6) + 2,5-dimethyl-1,4-hexadiene (927-97-9) + 5-chloro-2,5-dimethyl-hex-2-ene (90202-20-3)

Conditions	Yield
With pyridine; thionyl chloride for 4h; Ambient temperature;

2,5-dimethyl-hexa-3,4-dien-2-ol (2424-45-5) → 2,5-Dimethyl-2,4-hexadiene (764-13-6)

Conditions	Yield
With lithium aluminium tetrahydride In tetrahydrofuran at 80℃; for 21h;

2,5-Dimethyl-2,4-hexadiene (764-13-6) + β-naphthol (135-19-3) → 1-isopropyl-3,3-dimethyl-2,3-dihydro-1H-benzo[f]chromene (1039111-80-2)

Conditions	Yield
With [2,2]bipyridinyl; copper(II) bis(trifluoromethanesulfonate) In 1,2-dichloro-ethane at 50℃; for 18h;	99%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + C23H19NO2 (51029-29-9) → N-(2,5-dimethylhexa-1,4-dien-3-yl)benzohydroxamic acid (97476-44-3)

Conditions	Yield
In benzene at 80℃; for 5h;	94%

terephthalonitrile (623-26-7) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → (E)-4-(4-amino-1,1,4-trimethyl-2-pentenyl)benzonitrile

Conditions	Yield
With (R)-2,2'-methylenedioxy-1,1'-binaphthalene; ammonia In water; acetonitrile at 20℃; for 8h; Irradiation;	93%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + 1-acetoxy-2-aminoethane hydrochloride (20739-39-3) → ethyl trans-(+/-)-chrysanthemate (97-41-6, 1802-02-4, 7377-84-6, 15543-65-4, 16642-27-6, 34909-55-2, 41641-25-2, 41641-26-3, 41641-27-4)

Conditions	Yield
Stage #1: 1-acetoxy-2-aminoethane hydrochloride With sodium nitrite In water; 1,2-dichloro-ethane at -2 - 2℃; Stage #2: 2,5-Dimethyl-2,4-hexadiene With 2,6-di-tert-butyl-4-methyl-phenol; copper(l) chloride In 1,2-dichloro-ethane at 55 - 60℃;	92.63%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + thallium(III) triacetate (2570-63-0) → 4,5-diacetoxy-2,5-dimethylhex-2-ene (78796-71-1)

Conditions	Yield
In acetic anhydride; acetic acid at 65℃; for 15h;	92%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + thioacetic acid (507-09-5) → thioacetic acid S-(1-isopropyl-3-methyl-but-2-enyl) ester

Conditions	Yield
With indium(III) chloride In 1,2-dichloro-ethane at 80℃; for 0.25h;	92%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + di(4-tosyl)amine (3695-00-9) → (Z)-N-(2,5-dimethylhexa-2,4-dien-1-yl)-4-methyl-N-tosylbenzenesulfonamide (1374016-42-8)

Conditions	Yield
With acetoxy((4-methyl)-N-tosylbenzenesulfonamidyl)iodosobenzene In dichloromethane at 25℃; for 12h;	92%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + ((4-methyl-N-tosylphenyl)sulfonamido)(phenyl)-λ3-iodanyl acetate (1345824-06-7) + di(4-tosyl)amine (3695-00-9) → (Z)-N-(2,5-dimethylhexa-2,4-dien-1-yl)-4-methyl-N-tosylbenzenesulfonamide (1374016-42-8)

Conditions	Yield
In dichloromethane at 25℃;	92%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + GlyOEt*HCl (459-73-4) → ethyl 2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylate (97-41-6)

Conditions	Yield
Stage #1: GlyOEt*HCl With acetic acid; carbonic acid dimethyl ester at 20 - 28℃; pH=3.5 - 4.53; Large scale; Stage #2: 2,5-Dimethyl-2,4-hexadiene With copper(l) chloride at 90 - 95℃; Large scale;	92%

diazoacetic acid ethyl ester (623-73-4) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → ethyl 2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylate (97-41-6) + diethyl Fumarate (623-91-6) + Diethyl maleate (141-05-9)

Conditions	Yield
hexarhodium hexadecacarbonyl at 60℃; for 7h;	A 91% B n/a C n/a

diazoacetic acid ethyl ester (623-73-4) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → ethyl 2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylate (97-41-6)

Conditions	Yield
K-PFIEP[SO3 H] In dichloromethane	89.6%
Stage #1: 2,5-Dimethyl-2,4-hexadiene With dirhodium tetraacetate In dichloromethane for 0.5h; Stage #2: diazoacetic acid ethyl ester In dichloromethane at 20℃; for 24h; Reagent/catalyst;	80%
dirhodium tetraacetate at 25℃; Yield given;

2,5-Dimethyl-2,4-hexadiene (764-13-6) → (R)-2,4-dimethylhex-4-ene-2,3-diol (132312-00-6)

Conditions	Yield
With methanesulfonamide; 1,4-bis(9-O-dihydroquinidine)phthalazine In water; tert-butyl alcohol at 20℃; for 2h; Sharpless dihydroxylation;	89%
With methanesulfonamide; AD-mix β In water; tert-butyl alcohol at 0℃; for 20h; Sharpless dihydroxylation; Inert atmosphere; optical yield given as %ee; enantioselective reaction;	78%

4-ethoxycarbonyl-3-methyl-3-pyrazolin-5-one (125732-40-3) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → ethyl 3,5,5,8,8-pentamethyl-1-oxo-5,8-dihydro-1H-pyrazolo[1,2-a]pyridazin-2-carboxylate

Conditions	Yield
With lead(IV) acetate In dichloromethane at 20℃; for 3h; Diels-Alder reaction;	89%

diiodomethane (75-11-6) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → 1,1-dimethyl-2-(2-methyl-1-propenyl)cyclopropane (33422-32-1)

Conditions	Yield
With copper; zinc	87%

methanol (67-56-1) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → (3E,7E)-2,9-Dimethoxy-2,5,5,6,6,9-hexamethyl-deca-3,7-diene (80764-34-7)

Conditions	Yield
With 9-cyanophenanthrene at 20℃; for 20h; UV-irradiation;	87%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + t-butyl diazoacetate (35059-50-8) → (1S,3R)-3-(1-isobutenyl)-2,2-dimethylcyclopropanecarboxylic acid (84848-28-2) + 2,2-dimethyl-1R-trans-3-(2-methyl-propenyl)-cyclopropylcarboxylic acid tert-butyl ester (56194-30-0) + (1R,3S)-3-(1-isobutenyl)-2,2-dimethylcyclopropanecarboxylic acid (64312-83-0)

Conditions	Yield
With C25H30N2O2*Cu(1+)*CF3O3S(1-) In ethyl acetate at 0℃; for 3.5h; Reagent/catalyst; Inert atmosphere; Overall yield = 83 %; stereoselective reaction;	A n/a B 87% C n/a

9-vinyl-9H-carbazole (1484-13-5) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + dimethylglyoxal (431-03-8) → 9-{2-[(4R,5R)-4,5-Dimethyl-4,5-bis-((E)-1,1,4-trimethyl-pent-2-enyl)-[1,3,2]dioxaborolan-2-yl]-ethyl}-9H-carbazole

Conditions	Yield
Stage #1: 2,5-Dimethyl-2,4-hexadiene With borane-THF In tetrahydrofuran at 0℃; for 3h; Stage #2: 9-vinyl-9H-carbazole In tetrahydrofuran Stage #3: dimethylglyoxal In tetrahydrofuran at 20℃; for 12h;	86%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + (5,6-dihydro-1,4-dithiin-2-yl)methanol (199393-68-5) → 6,6-dimethyl-5-(2-methylprop-1-en-1-yl)-3,5,6,7-tetrahydro-2H-cyclopenta[b][1,4]dithiine

Conditions	Yield
With trifluoroacetic acid In dichloromethane at -78 - 20℃; Inert atmosphere;	85%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + 3,5-di-tert-butyl-o-benzoquinone (3383-21-9) → 5,7-Bis-(1,1-dimethylethyl)-2,2-dimethyl-3-(2-methylprop-1-enyl)-1,4-benzodioxine

Conditions	Yield
In toluene at 120℃; for 30h;	84%
at 100℃; for 2h;	84%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + tris(dimethylamino)sulfonium salt of 2,2,2-trifluoro-1-(trifluoromethyl)ethanesulfonyl fluoride (109183-85-9) → 2,2-bis(trifluoromethyl)-3-<2-methyl-1-propenyl>-4,4-dimethyl-1-thietane 1,1-dioxide (109183-91-7)

Conditions	Yield
With silicon tetrafluoride In acetonitrile at 0 - 25℃;	83%

2,5-Dimethyl-2,4-hexadiene (764-13-6) → 4-iodo-2,2,5,5-tetramethyltetrahydrofuran-3-ol

Conditions	Yield
With tert-butylhypochlorite; Trifluoromethanesulfonamide; sodium iodide In acetonitrile at 20℃; Darkness;	83%

potassium hydrogen difluoride + borane-THF (14044-65-6) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → potassium (E)-trifluoro(prop-1-en-1-yl)trifluoroborate

Conditions	Yield
Stage #1: borane-THF; 2,5-Dimethyl-2,4-hexadiene In tetrahydrofuran at 0 - 5℃; for 4h; Stage #2: With prop-1-yne at 0 - 20℃; for 12h; Stage #3: potassium hydrogen difluoride Further stages;	83%

terephthalonitrile (623-26-7) + methanol (67-56-1) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → trans-2-(4-cyanophenyl)-5-methoxy-2,5-dimethyl-3-hexene

Conditions	Yield
With biphenyl In acetonitrile at 10℃; for 26h; Irradiation;	82%

terephthalonitrile (623-26-7) + methanol (67-56-1) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → trans-2-(4-cyanophenyl)-5-methoxy-2,5-dimethyl-3-hexene + trans-5-(4-cyanophenyl)-2,2,5-trimethyl-3-hexenenitrile

Conditions	Yield
With biphenyl In acetonitrile for 18h; Irradiation;	A 82% B 2%

1,2-dihydro-5-methyl-3H-pyrazol-3-one (4344-87-0) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) → 3,5,5,8,8-pentamethyl-5,8-dihydro-1H-pyrazolo[1,2-a]pyridazin-1-one

Conditions	Yield
With lead(IV) acetate In dichloromethane at 20℃; for 3h; Diels-Alder reaction;	81%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + 2,6-di-tert-butyl-4-methylphenyl diazoacetate (125640-92-8) → 2,6-di-tert-butyl-4-methylphenyl trans-2-(2-methyl-1-propenyl)-3,3-dimethylcyclopropanecarboxylate (125641-39-6, 125664-81-5, 139068-75-0, 139068-76-1)

Conditions	Yield
dirhodium tetraacetate In dichloromethane for 2h; Ambient temperature;	80%

terephthalonitrile (623-26-7) + 2,5-Dimethyl-2,4-hexadiene (764-13-6) + potassium cyanide (151-50-8) → trans-5-(4-cyanophenyl)-2,2,5-trimethyl-3-hexenenitrile

Conditions	Yield
With 18-crown-6 ether; biphenyl In acetonitrile for 24h; Irradiation;	80%

2,5-Dimethyl-2,4-hexadiene (764-13-6) + N-(2-ethoxy-1-naphthoyl)pyrrolidine (908517-95-3) → C26H34O2

Conditions	Yield
Irradiation;	80%

Upstream product

• 3017-69-4 2-methyl-1-propenylbromide 
• 15331-16-5 1,1,2-tribromo-2-methyl-propane 
• 6223-78-5 2,5-dichloro-2,5-dimethyl hexane 
• 60703-31-3 2,5-dimethyl-2-hexen-4-ol 
• 2431-30-3 2,5-dichloro-2,5-dimethyl-3-hexyne 
• 625-86-5 2,5-dimethylfuran 
• 75-16-1 methylmagnesium bromide 
• 638-02-8 2,5-DIMETHYLTHIOPHENE 
• 623-26-7 terephthalonitrile 
• 67-56-1 methanol 
• 927-97-9 2,5-dimethyl-1,4-hexadiene 
• 110-03-2 2,5-dimethyl-2,5-hexanediol 
• 86119-84-8 phosphoric acid 
• 64-17-5 ethanol 

Downstream Products

• 100314-28-1 2-isopropyl-4,6-dimethyl-cyclohex-3-enecarbaldehyde 
• 15045-43-9 2,2,5,5-tetramethyltetrahydrofuran 
• 22966-70-7 2,5-dichloro-2,5-dimethyl-hex-3t-ene 
• 692-70-6 (E)-2,5-dimethylhex-3-ene 
• 6223-78-5 2,5-dichloro-2,5-dimethyl hexane 
• 827-90-7 trans-chrysanthemic acid 
• 2935-23-1 cis-Chrysanthemic acid 
• 36597-09-8 4-methyl-1-phenyl-3-penten-1-one 
• 93719-54-1 trans--2-<4-Chlor-phenylthio>-2,5-dimethyl-hex-3-en-5-yl-hydroperoxid 
• 5460-63-9 methyl (dl)-trans-chrysanthemate 
• 5460-63-9 (+/-)-cis-Chrysanthemsaeure-methylester 
• 110243-06-6 6,6-Dimethyl-7-(2-methyl-propenyl)-3-phenyl-1,3,5-triaza-bicyclo[3.2.0]heptane-2,4-dione 
• 110243-07-7 1-(1-Isopropenyl-3-methyl-but-2-enyl)-4-phenyl-[1,2,4]triazolidine-3,5-dione 
• 106344-68-7 (E)-2-methyl-3-(3-methylbut-2-enylidene)-2,3-dihydro-2-azaphenalen-1-one 

Relevant articles and documents

2,2,5,5-Tetramethyltetrahydrofuran (TMTHF): A non-polar, non-peroxide forming ether replacement for hazardous hydrocarbon solvents

An inherently non-peroxide forming ether solvent, 2,2,5,5-tetramethyltetrahydrofuran (2,2,5,5-tetramethyloxolane), has been synthesized from readily available and potentially renewable feedstocks, and its solvation properties have been tested. Unlike traditional ethers, its absence of a proton at the alpha-position to the oxygen of the ether eliminates the potential to form hazardous peroxides. Additionally, this unusual structure leads to lower basicity compared with many traditional ethers, due to the concealment of the ethereal oxygen by four bulky methyl groups at the alpha-position. As such, this molecule exhibits similar solvent properties to common hydrocarbon solvents, particularly toluene. Its solvent properties have been proved by testing its performance in Fischer esterification, amidation and Grignard reactions. TMTHF's differences from traditional ethers is further demonstrated by its ability to produce high molecular weight radical-initiated polymers for use as pressure-sensitive adhesives.

VARIATIONS ON PRINS-LIKE CHEMISTRY TO PRODUCE 2,5-DIMETHYLHEXADIENE FROM ISOBUTANOL

The method of the present invention provides a high yield pathway to 2,5-dimethylhexadiene from renewable isobutanol, which enables economic production of renewable p-xylene (and subsequently, terephthalic acid, a key monomer in the production of PET) from isobutanol. In addition, the present invention provides methods for producing 2,5-dimethylhexadiene from a variety of feed stocks that can act as “equivalents” of isobutylene and/or isobutyraldehyde including isobutanol, isobutylene oxide, and isobutyl ethers and acetals. Catalysts employed in the present methods that produce 2,5-dimethylhexadiene can also catalyze alcohol dehydration, alcohol oxidation, epoxide rearrangement, and ether and acetal cleavage.