Alpha Pinene Overview

Alpha Pinene is an organic compound of the terpene class, one of two isomers of pinene. It is an alkene and it contains a reactive four-membered ring. It is found in the oils of many species of many coniferous trees, notably the pine. Both enantiomers are known in nature; 1S,5S- or (−)-α-pinene is commoner in European pines, whereas the 1R,5R- or (+)-α-isomer is commoner in North America. The racemic mixture is present in some oils such as eucalyptus oil.

The four membered ring in α-pinene 1 makes it a reactive hydrocarbon, prone to skeletal rearrangements such as the Wagner-Meerwein rearrangement. For example, attempts to perform hydration or hydrogen halide addition with the alkene functionality typically lead to rearranged products. Of under acidic conditions. With concentrated sulfuric acid and ethanol the major products are terpineol 2 and its ethyl ether 3, while glacial acetic acid gives the corresponding acetate ester 4. With dilute acids, terpin hydrate 5 becomes the major product.

With one molar equivalent of anhydrous HCl, the simple addition product 6a can be formed at low temperature in the presence of ether, but it is very unstable. At normal temperatures, or if no ether is present, the major product is bornyl chloride 6b, along with a small amount of fenchyl chloride 6c. For many years 6b (also called “artificial camphor”) was referred to as “pinene hydrochloride”, until it was confirmed as identical with bornyl chloride made from camphene. If more HCl is used, achiral 7 (dipentene hydrochloride) is the major product along with some 6b. Nitrosyl chloride followed by base leads to the oxime 8 which can be reduced to “pinylamine” 9. Both 8 and 9 are stable compounds containing an intact four-membered ring, and these compounds helped greatly in identifying this important component of the pinene skeleton. A variety of reagents such as iodine or PCl3 cause aromatization, leading to p-cymene 10.

α-Pinene is an organic compound of the terpene class, one of two isomers of pinene. It is an alkene and it contains a reactive four-membered ring. It is found in the oils of many species of many coniferous trees, notably the pine. Both enantiomers are known in nature; 1S,5S- or (−)-α-pinene is commoner in European pines, whereas the 1R,5R- or (+)-α-isomer is commoner in North America. The racemic mixture is present in some oils such as eucalyptus oil.

The four-membered ring in α-pinene 1 makes it a reactive hydrocarbon, prone to skeletal rearrangements such as the Wagner-Meerwein rearrangement. For example, attempts to perform hydration or hydrogen halide addition with the alkene functionality typically lead to rearranged products. Of under acidic conditions. With concentrated sulfuric acid and ethanol the major products are terpineol 2 and its ethyl ether 3, while glacial acetic acid gives the corresponding acetate ester 4. With dilute acids, terpin hydrate 5 becomes the major product.

With one molar equivalent of anhydrous HCl, the simple addition product 6a can be formed at low temperature in the presence of ether, but it is very unstable. At normal temperatures, or if no ether is present, the major product is bornyl chloride 6b, along with a small amount of fenchyl chloride 6c. For many years 6b (also called “artificial camphor”) was referred to as “pinene hydrochloride”, until it was confirmed as identical with bornyl chloride made from camphene. If more HCl is used, achiral 7 (dipentene hydrochloride) is the major product along with some 6b.

 

Nitrosyl chloride followed by base leads to the oxime 8 which can be reduced to “pinylamine” 9. Both 8 and 9 are stable compounds containing an intact four-membered ring, and these compounds helped greatly in identifying this important component of the pinene skeleton. A variety of reagents such as iodine or PCl3 cause aromatization, leading to p-cymene 10.

 

Product Specification — Alpha-Pinene Indonesia

SPECIFICATION STANDARD RESULT
SNI 01-5009.3-2001 Cos No. 039/II/2004
1 SPECIFIC GRAFITY AT 25° C 0.848 – 0.865 0,8553
2 REFRACTIVE INDEX AT 25° C 1.464 – 1.478 1,4651
3 FATTY OIL Negative Negative
4 FLASH POINT 33° C – 38° C 36,5° C
5 DISTILATION TEMPERATURE AT 760 MM HG 150° C – 160° C 157,4° C
6 RESIDU AFTER POLYMERIZATION WITH 38 N NH2SO4 Grade A : ≤ 2 % 1,91%
B : > 2 %
7 DISTILAT UNDER TEMPERATURE 170° C Grade A : ≥ 90 % 92,0%
B : < 90 %
8 COLOUR Clear Clear
9 ALPHA PINENE CONTENT Grade A : ≥ 80 % 82,10 %
B : < 80 %
10 OPTICAL ROTATION Grade A : + ≥ 32° C + 32,15°
B : + < 32° C
Grade A (PRIMARY)

 

PRODUCT IDENTIFICATION

CAS NO. : 80-56-8
FORMULA : C10H16
MOL WT. : 136.24
H.S. CODE : 29021900
SYNONYMS : -2-Pinene; -alpha-Pinene         

 
 
 
 
 
 
 
 

PHYSICAL AND CHEMICAL PROPERTIES

MELTING POINT : −64˚ C (209 K)
BOILING POINT : 155˚ C (428 K
SPECIFIC GRAVITY : 0.858 g/mL, liquid at 20˚ C
SOLUBILITY IN WATER : Very low