765-47-9

Basic information

• Product Name: 1,2-DIMETHYLCYCLOPENTENE
• Synonyms: 1,2-dimethyl-1-cyclopentene;cyclopentene,1,2-dimethyl-;1,2-DIMETHYLCYCLOPENTENE;1,2-Dimrthylcyclopentene
• CAS NO: 765-47-9
• Molecular Formula: C₇H₁₂
• Molecular Weight: 96.17
• EINECS: 212-148-5
• Mol File: 765-47-9.mol

Chemical Properties

• Melting Point: -90.4°C
• Boiling Point: 102.85°C
• Appearance: /
• Density: 0.7928
• Vapor Pressure: 33.9mmHg at 25°C
• Refractive Index: 1.4420
• CAS DataBase Reference: 1,2-DIMETHYLCYCLOPENTENE(CAS DataBase Reference)
• NIST Chemistry Reference: 1,2-DIMETHYLCYCLOPENTENE(765-47-9)
• EPA Substance Registry System: 1,2-DIMETHYLCYCLOPENTENE(765-47-9)

Safety Data

• Hazardous Substances Data: 765-47-9(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Industry:
1,2-Dimethylcyclopentene is used as a synthetic intermediate for the production of various pharmaceutical compounds. Its unique structure allows for the synthesis of complex molecules that can be used in the development of new drugs.
Used in Food Industry:
1,2-Dimethylcyclopentene is used as a synthetic intermediate in the production of certain food additives and flavorings. Its ability to form complex molecules makes it a valuable component in the creation of unique tastes and scents.
Used in Plastic Industry:
1,2-Dimethylcyclopentene is used as a synthetic intermediate in the production of certain types of plastics. Its potential to form complex structures allows for the development of new plastic materials with improved properties.
Used in Pesticide Industry:
1,2-Dimethylcyclopentene is used as a synthetic intermediate in the production of certain pesticides. Its ability to form complex molecules can lead to the development of new and more effective pest control agents.
Note: Due to the potential instability and explosiveness of 1,2-dimethylcyclopentene, it is crucial to handle this chemical with caution and use appropriate personal protective equipment to ensure safety and health.

InChI:InChI=1/C7H12/c1-6-4-3-5-7(6)2/h3-5H2,1-2H3

Upstream product

• 16240-42-9 1,2-epoxy-1-methylcyclopentane 
• 917-64-6 methyl magnesium iodide 
• 60-29-7 diethyl ether 
• 82166-21-0 methyl cyclohexane 
• 1192-18-3 cis-1,2-dimethylcyclopentane 
• 822-50-4 trans-1,2-dimethylcyclopentane 
• 2532-58-3 cis-1,3-dimethylcyclopentane 
• 1759-58-6 trans-1,3-dimethylcyclopentane 
• 1120-72-5 2-Methylcyclopentanone 
• 591-47-9 4-methylcyclohexene 
• 591-49-1 1-methylcyclohex-1-ene 
• 10472-24-9 methyl 2-oxocyclopentane-1-carboxylate 
• 7664-93-9 sulfuric acid 
• 59383-67-4 2-cyclobutyl-propan-2-ol 

Downstream Products

• 13505-34-5 2,6-heptandione 
• 822-50-4 1,2-dimethylcyclopentane 
• 1192-18-3 cis-1,2-dimethylcyclopentane 
• 822-50-4 trans-1,2-dimethylcyclopentane 
• 64-18-6 formic acid 
• 3128-06-1 5-ketohexanoic acid 
• 65-85-0 benzoic acid 
• 7417-68-7 2,5-dihydroxy-4-methoxytoluene 
• 72312-09-5 (3aR,4R,8S,8aR,9S)-9-Hydroxy-6-methoxy-3a,8,8a-trimethyl-2,3,3a,4,8,8a-hexahydro-1H-4,8-methano-azulen-5-one 
• 614-13-1 2-methoxy-5-methyl-1,4-benzoquinone 
• 41410-53-1 (+/-)-gymnomitrol 
• 82022-31-9 (3aR,4R,8S,8aR)-6-Methoxy-3a,8,8a-trimethyl-2,3,3a,4,8,8a-hexahydro-1H-4,8-methano-azulene-5,9-dione 
• 82022-31-9 (3aR,4S,8R,8aR)-6-Methoxy-3a,8,8a-trimethyl-2,3,3a,4,8,8a-hexahydro-1H-4,8-methano-azulene-5,9-dione 
• 4541-32-6 2,2-dimethylcyclopentanone 

Relevant articles and documents

Stereochemical Effects in the Gas-Phase Pinacol Rearrangement of cis- and trans-1,2-Dimethylcyclopentane-1,2-diol

The pinacol rearrangement of cis- and trans-1,2-dimethylcyclopentane-1,2-diol, promoted by the gaseous Broensted acids D3+, CH5+/C2H5+, and t-C4H9+, was studied by mass spectrometric and radiolytic methods.Dehydration of the protonated substrate is rate limiting, and competitive experiments with pinacol, carried out at high pressure (760 torr), showed that the cis rearranges more rapidly than the trans isomer, indicating participation of the migrating methyl group to the leaving water molecule.The results are compared with those concerning the same substrates in solution, where no evidence of anchimeric assistance was found.

MECHANISM OF SOLVOLYSIS OF 2,2-DIMETHYLCYCLOPENTYL P-BROMOBENZENESULFONATE

Solvolysis of the title compound in ethanol-water, trifluoroethanol-water, and hexafluoroisopropyl alcohol-water mixtures yields > 90 percent products of methyl migration.The rate of solvolysis relative to the cyclopentyl analogue is 0.19 in 80 percent ethanol-water, 4.0 in 97 percent trifluoroethanol-water, and 10.0 in 90 percent hexafluoroisopropyl alcohol-water.The α-d and β-d2 rate effects in solvolysis range respectively from 1.19-1.20 to 1.26-1.30.The results are interpreted in terms of a mechanism which involves reversible formatin of the tight ion pair followed by rate-determining methyl migration.

Protium-deuterium exchange of cyclic and acyclic alkanens in dilute acid medium at elevated temperatures

A modification of the high temperature - dilute acid (HTDA) method for deuterium labelling of aromatic compounds has been applied to the H-D exchange of a number of cyclic and acyclic alkenes.Cyclopentene, cyclohexene, cyclododecene, and tetramethylethylene have been completely exchanged in excellent yield. 1-Methylcyclopentene and 1-methylcyclohexene have also been perdeuterated and cycloheptene and cyclooctene partially labelled but require spinning band distillation or preparative glpc for separation from rearrangement products.A variety of C5-C8 acyclic alkeneshave also been treated under HTDA conditions.

Oxidation by cobalt(III)acetate. Part 9. Effect of substituents on the oxidative Cleavage of glycols in acetic acid

The kinetics of oxidative cleavage of glycols by obalt(III) acetate in acetic acid have been studied.The substrates examined include cis- and trans-cyclopentane- and cyclohexane-1,2-diols and their mono- and dimethyl derivatives.The rates were first-order in both cobalt(III)acetate and substrate in all cases.In the oxidation of five-membered ring diols, cis-diols were generally oxidized faster than the trans-isomers.Complex results were obtained in the case of six-membered ring diols.Thermodynamic parameters were calculated for all the substrates.A mechanism involving a bidente complex of cobalt(III) acetate dimer and glycol is sugge sted, except for the case of trans-cyclopentane-1,2-diols, for which a monodentate intermediate is proposed.

A SYNTHESIS OF GYMNOMITROL

Condensation of 1,2-dimethylcyclopentene 10 with 2-methyl-4,4,5-trimethoxycyclohexa-2,5-dienone 7 in methylene chloride-nitromethane with added stannic chloride gave a mixture of the two diastereomeric bicyclooctanes 13 and 14 by ionic cycloaddition.After selective reduction of the saturated carbonyl group with sodium borohydride, and hydrogenation of the double bond the two epimers 18 and 20 (ratio 3.3:1) were separable by chromatography.Protection of the hydroxy group in 18 with dihydropyran and, reduction of the α-methoxyketone 19 with calcium in liquid ammonia gave ketone 21.Gymnomitrol 1 was then prepared by Wittig olefination followed by deprotection of the hydroxy group.

A synthesis of gymnomitrol

Condensation of 1,2 - dimethylcyclopentene 10 with 2 - methyl - 4,4, 5 - trimethoxycyclohexa - 2,5 -dienone 7 in methylene chloride - nitromethane with added stannic chloride gave a mixture of the two diastereomeric bicycle[3.2.1]octanes 13 and 14 by ionic [4+2]cycloaddition. After selective reduction of the saturated carbonyl group with sodium borohydride, and hydrogenation of the double bond the two epimers 18 and 20 (ratio 3.3:1) were separable by chromatography. Protection of the hydroxy group in 18 with dihydropyran and, reduction of the α-methoxyketone 19 with calcium in liquid ammonia gave ketone 21. Gymnomitrol 1 was then prepared by Wittig olefination followed by deprotection of the hydroxy group.

A synthesis of gymnomitrol

Condensation of 1,2 - dimethylcyclopentene 10 with 2 - methyl - 4,4, 5 - trimethoxycyclohexa - 2,5 -dienone 7 in methylene chloride - nitromethane with added stannic chloride gave a mixture of the two diastereo-meric bicyclo[3.2.1]octanes 13 and 14 by ionic [4+2]cycloaddition. After selective reduction of the saturated carbonyl group with sodium borohydride, and hydrogenation of the double bond the two epimers 18 and 20 (ratio 3.3:1) were separable by chromatography. Protection of the hydroxy group in 18 with dihydropyran and, reduction of the α-methoxyketone 19 with calcium in liquid ammonia gave ketone 21. Gymnomitrol 1 was then prepared by Wittig olefination followed by deprotection of the hydroxy group.