Pinane (chemical compound)

Structural formula
	Structural formula with no clear stereochemistry
General
Surname	Pinan
other names	2,6,6-trimethylbicyclo [3.1.1] heptane; Dihydropins;
Molecular formula	C 10 H 18
Brief description	colorless liquid
External identifiers / databases
EC number	207-467-1
ECHA InfoCard	100.006.790
PubChem	10129
ChemSpider	9724
Wikidata	Q2095373
properties
Molar mass	138.26 g mol −1
Physical state	liquid
density	0.86 g cm −3
Melting point	−53 ° C
boiling point	168 ° C
Vapor pressure	3.33 h Pa (20 ° C)
solubility	almost insoluble in water
Refractive index	1.4624
safety instructions
H and P phrases	H: 226-411
	P: 210-262
Toxicological data	> 5000 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Pinan (stress on the second syllable: Pin a n ) is an organic chemical compound that belongs to the group of bicyclic hydrocarbons and monoterpenes . It is a colorless, oily liquid with a characteristic, turpentine- like odor.

Occurrence

In addition to other hydrocarbons, pinane is found in vegetable oils, e.g. For example, up to 15.8% pinane was found in an extract obtained from the Argentine medicinal plant Mutisia friesiana by steam distillation .

Manufacturing

Pinane can be produced from pinene by catalytic hydrogenation with hydrogen over platinum, palladium or nickel catalysts or complex iron catalysts . This creates a mixture of exo and endo pinane (also called cis and trans pinane), with the former being formed in significant excess.

Interestingly, if a mixture of α- and β-pinene is used as the starting substance when using complex iron (II) catalysts, only the β-isomer reacts.

properties

Pinan is a representative of the monoterpenes, a chemical substance class of hydrocarbons with the empirical formula C ₁₀ H ₁₈ . Thus it is also an isomer of many other monoterpenes, e.g. B. the camphan . The basic structure consists of a six-membered carbon ring (see: cyclohexane ) with a "bridge" that contains a carbon atom. This structure still has three methyl groups in the pinane, two of which are on the “bridge”.

Stereoisomers

The described arrangement of the molecule makes it chiral and contains three centers of chirality . Theoretically, eight stereoisomers would be possible, but since the configurations of the linking atoms of the “bridge” (1 and 5) depend on one another for spatial reasons , there are only four stereoisomers.

The different stereoisomers of pinane

Explanation of the figure: In the figures, the numbering of the framework atoms on which the systematic name of the pinane is based is noted in black digits. The two pinanes highlighted in yellow are enantiomeric to each other (mirror images ); the same applies to the two structures on a white background. The "bridge" mentioned in the text above is marked in green. If the methyl group (on C atom 2) is on the same side (blue) of the 6-ring as the bridge, this is referred to as a cis or exo configuration. If the methyl group is on the side of the 6-ring ring facing away from the bridge (red), a trans - or endo -pinane is present. The indications (+) and (-) in the alternative designations refer to the sign of the rotation value of the connections. The series of numbers in square brackets are the CAS registration numbers of the pure, individual stereoisomers.

Chemical properties

As a hydrocarbon, pinane is inert to many mild reaction conditions, but it can be oxidized to pinane-2- hydroperoxide at elevated temperatures (approx. 100 ° C) in the presence of oxygen , with both the cis and the trans -pinane predominantly the cis -hydroperoxide is formed.

use

In organic synthetic chemistry, pinane is occasionally used as a starting material for the synthesis of substances with terpene skeletons. If the above-mentioned oxidation with oxygen is based on stereoisomerically pure pinane, the hydroperoxide obtained can be used as a chiral oxidizing agent for the stereoselective oxidation of other substances.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Pinan data sheet (PDF) from Merck , accessed on April 20, 2011.

↑ Entry on Pinan. In: Römpp Online . Georg Thieme Verlag, accessed on November 10, 2014.

↑ Pinan data sheet at Acros, accessed on February 20, 2010.

^ RT O'Connor, LA Goldblatt: Correlation of Ultraviolet and Infrared Spectra of Terpene Hydrocarbons , in: Anal. Chem. , 1954 , 26 , pp. 1726-1737; doi : 10.1021 / ac60095a014 .

↑ CI Viturro, J. De la Fuente: Proceedings of the 12th National Symposium of Organic Chemistry (XII SINAQO), Los Cocos, Cordoba, Argentina 14-17 November 1999 In: Molecules , 2000 , 5 , pp 568-570 ( PDF file; 1.85 MB).

↑ ^a ^b T. P. Sieber: Development of new homogeneous iron hydrogenation catalysts with diazadiene or diazatriene ligands , dissertation Zurich 2000 , pp. 103, 104 and 219 (PDF; 2.9 MB).

↑ GS Fisher, JS Stinson, LA Goldblatt, J. Am. Chem. Soc. , 1953 , 75 , pp. 3675-3678.

↑ GA Schmidt, GS Fisher, J. Am. Chem. Soc. , 1959 , 81 , pp. 445-448.

[Merck-1] ↑ ^a ^b ^c ^d ^e ^f ^g Pinan data sheet (PDF) from Merck , accessed on April 20, 2011.

[roempp-2] Entry on Pinan. In: Römpp Online . Georg Thieme Verlag, accessed on November 10, 2014.

[3] Pinan data sheet at Acros, accessed on February 20, 2010.

[4] RT O'Connor, LA Goldblatt: Correlation of Ultraviolet and Infrared Spectra of Terpene Hydrocarbons , in: Anal. Chem. , 1954 , 26 , pp. 1726-1737; doi : 10.1021 / ac60095a014 .

[5] CI Viturro, J. De la Fuente: Proceedings of the 12th National Symposium of Organic Chemistry (XII SINAQO), Los Cocos, Cordoba, Argentina 14-17 November 1999 In: Molecules , 2000 , 5 , pp 568-570 ( PDF file; 1.85 MB).

[Sieber-6] T. P. Sieber: Development of new homogeneous iron hydrogenation catalysts with diazadiene or diazatriene ligands , dissertation Zurich 2000 , pp. 103, 104 and 219 (PDF; 2.9 MB).

[7] GS Fisher, JS Stinson, LA Goldblatt, J. Am. Chem. Soc. , 1953 , 75 , pp. 3675-3678.

[8] GA Schmidt, GS Fisher, J. Am. Chem. Soc. , 1959 , 81 , pp. 445-448.