7705-14-8

Basic information

• Product Name: DIPENTENE
• Synonyms: Terpineolene;Cyclohexene, 1-methyl-4-(1-methyl-,;rac-1-Methyl-4α*-(1-methylethenyl)cyclohexene;(+/-)-1-Methyl-4-(1-methylvinyl)cyclohexene;Cyclohexene, 1-methyl-4-(1-methylethenyl)-, (±DL-4-Isopropenyl-1-methylcyclohexene;Mentha-1,8-diene (dl);p-Mentha-1,8-diene, (±
• CAS NO: 7705-14-8
• Molecular Formula: C₁₀H₁₆
• Molecular Weight: 136.23
• EINECS: 205-341-0
• Mol File: 7705-14-8.mol
• Article Data: 2

Chemical Properties

• Melting Point: -74 °C
• Boiling Point: 170-180 °C(lit.)
• Flash Point: 110 °F
• Appearance: /
• Density: 0.86 g/mL at 20 °C(lit.)
• Vapor Density: >4.7 (80 °C, vs air)
• Vapor Pressure: 1 mm Hg ( 20 °C)
• Refractive Index: n20/D 1.473(lit.)
• Water Solubility: <1 g/100mL
• CAS DataBase Reference: DIPENTENE(CAS DataBase Reference)
• NIST Chemistry Reference: DIPENTENE(7705-14-8)
• EPA Substance Registry System: DIPENTENE(7705-14-8)

Safety Data

• Hazard Codes: Xi,N
• Statements: 10-38-43-50/53
• Safety Statements: 24-37-60-61
• RIDADR: UN 2052 3/PG 3
• WGK Germany: 1
• RTECS: OS8100000
• Hazardous Substances Data: 7705-14-8(Hazardous Substances Data)

Usage

Description

dl-Limonene has a pleasant, lemon-like odor free from campho raceous and turpentine-like notes. The most important and wide spread terpene; it is known in the d- and ι- optically active forms and in the optically inactive dl-iovm (known as dipentene); it has been reported found in more than 300 essential oils in amounts ranging from 90 - 95% (lemon, orange, mandarin) to as low as 1% (palmarosa); the most widespread form is the d-limonene, followed by the racemic form, and then ι-limonene.

InChI:InChI=1/C10H16/c1-8(2)10-6-4-9(3)5-7-10/h4,10H,1,5-7H2,2-3H3/t10-/m1/s1

Upstream product

• 7785-26-4 (-)-α-pinene 
• 1071035-30-7 Phosphoric acid 1-cyano-5-isopropenyl-2-methyl-cyclohex-2-enyl ester diethyl ester 

Downstream Products

• 72152-81-9 trans-Carvyl phenylacetate 
• 72152-81-9 cis-Carvyl phenylacetate 
• 73524-01-3 cis-Carvyl benzoate 
• 73524-01-3 trans-carveol benzoate 
• 97-42-7 carvyl acetate 
• 99-48-9 5-Isopropenyl-2-methyl-cyclohex-2-enol 
• 99-49-0 Carvone 
• 30808-80-1 trans-6-chloro-p-mentha-1,8-diene 

Relevant articles and documents

The kinetics, stereochemistry, and deuterium isotope effects in the α-pinene pyrolysis. Evidence for incursion of multiple conformations of a diradical

Pyrolysis of optically active α-pinene gave 95% racemic limonene (dipentene), alloocimine, racemic α-pinene, α-pyronene. Activation parameters are reported. Pyrolysis of (S) syn-6-trideuteriomethyl α-pinene at 256.7°C for 2400s gave dipentene with twice as much deuterium as hydrogen transfer with kH/kD=1.49 and alloocimine with a Z and E trideuteriomethyl ratio of ca. 5 with kH/kD=0.89. The isotope effect on loss of starting material was 1.16. Separation of the enantiomers of α-pinene from 3600s pyrolyses at 256.7°C followed by NMR analysis revealed that the ratio of the R-syn to R-anti to S-anti isomers is 4.6:3.7:1 at roughly two half-lives. Kinetic analysis reveals that the previously proposed mechanism for all conversions involving slow interconversion of two diradicals with Cs symmetry is not consistent with the distribution of the ??-pinene isomers, particularly the formation of more suprafacial-retention product (R-anti) than bond-rotated isomer (S-anti). Inclusion of another Cs species (ignoring the deuteriums) that would be intermediate between the originally proposed Cs species, appears more consistent with the observations.