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
• Article Data: 7

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

General Description

1,2-Dimethylcyclopentene is a colorless liquid organic compound that belongs to a class of compounds known as cycloalkenes, specifically, a cyclic alkene with two additional methyl groups attached. It has a strong pungent odor. Its molecular formula is C7H12, indicating it consists of seven carbon atoms and 12 hydrogen atoms. It has potential use in various industries such as food, pharmaceutical, plastic, and pesticide due to its potential as a synthetic intermediate. However, it does not appear to be widely used or commercially available due to its potential for instability and explosiveness. The safety and health effects of 1,2-dimethylcyclopentene are not well studied, therefore, adequate personal protective equipment is recommended when handling this chemical.

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

Upstream product

• 19550-45-9 1,2-Dimethylcyclopentan-1-ol 
• 59383-67-4 2-cyclobutyl-propan-2-ol 
• 56404-39-8 (+/-)-1-r-acetoxy-1,2t-dimethyl-cyclopentane 
• 16240-42-9 1,2-epoxy-1-methylcyclopentane 
• 917-64-6 methyl magnesium iodide 
• 60-29-7 diethyl ether 
• 82166-21-0 methyl cyclohexane 
• 591-49-1 1-methylcyclohex-1-ene 
• 16491-15-9 1,5-dimethylcyclopentene 
• 104-15-4 toluene-4-sulfonic acid 
• 64-18-6 formic acid 
• 144-62-7 oxalic acid 
• 56404-39-8 (+/-)-1-r-acetoxy-1,2c-dimethyl-cyclopentane 
• 1120-72-5 2-Methylcyclopentanone 

Downstream Products

• 82461-31-2 1,5-dimethyl-6-oxabicyclo[3.1.0]hexane 
• 19987-14-5 1,5-dimethyl-6,7,8-trioxa-bicyclo[3.2.1]octane 
• 13505-34-5 2,6-heptandione 
• 5185-97-7 4-oxopentyl acetate 
• 13984-50-4 methyl levulinate 
• 33046-20-7 1,2-dimethyl-cyclopentane-1r,2t-diol 
• 626-96-0 4-oxopentanal 
• 123-76-2 levulinic acid 
• 64-18-6 formic acid 
• 3128-06-1 5-ketohexanoic acid 
• 65-85-0 benzoic acid 
• 110-15-6 succinic acid 
• 144-62-7 oxalic acid 
• 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 

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.

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.

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.