Title: b-Pinene
CAS Registry Number: 127-91-3
CAS Name: 6,6-Dimethyl-2-methylenebicyclo[3.1.1]heptane
Additional Names: nopinene
Molecular Formula: C10H16
Molecular Weight: 136.23
Percent Composition: C 88.16%, H 11.84%
Literature References: Found in most essential oils which contain a-pinene, but in far smaller proportions; the l-form occurs most commonly. Initial identification: A. von Baeyer, Ber. 29, 25 (1896). Isoln of the d-form from Ferula galbaniflua Boiss. et Buhse, Umbelliferae: B. N. Rutovski, I. V. Vinogradova, J. Prakt. Chem. 120, 41 (1928); from Cynomarathrum nuttallii A. Gray, Umbelliferae: E. K. Nelson, J. Am. Chem. Soc. 55, 3400 (1933). Irreversible isomerization of b-pinene to a-pinene occurs on shaking with platinum black satd with hydrogen: F. Richter, W. Wolff, Ber. 59, 1733 (1926). Synthesis: G. Bonnet, Bull. Inst. Pin 1938, 217; 1939, 1, C.A. 33, 42234 (1939); K. J. Crowley, Proc. Chem. Soc. London 1962, 245; Tetrahedron 21, 1001 (1965); L. M. Harwood, M. Julia, Synthesis 1980, 456. For general refs see a-pinene.
Derivative Type: dl-Form
Properties: bp760 165-166°.
Boiling point: bp760 165-166°
Derivative Type: d-Form
Properties: bp760 164-166°. d2020 0.8654. nD20 1.4739. [a]D +28.59° (Nelson). Also reported as bp760 162-163°. d2020 0.8662. nD20 1.4745. [a]D +20.75° (Rutovski, Vinogradova).
Boiling point: bp760 164-166°; bp760 162-163°
Optical Rotation: [a]D +28.59° (Nelson); [a]D +20.75° (Rutovski, Vinogradova)
Index of refraction: nD20 1.4739; nD20 1.4745
Density: d2020 0.8654; d2020 0.8662
Derivative Type: l-Form
Properties: bp760 162-163°. d15 0.874. nD15 1.4872, [a]D -22.4°.
Boiling point: bp760 162-163°
Optical Rotation: [a]D -22.4°
Index of refraction: nD15 1.4872
Density: d15 0.874
beta-Propiolactone beta-Resorcylaldehyde beta-Resorcylic Acid beta-Santalol Betasine

(1S)-(-)-beta-pinene-2D-projected-skeletal.png (1S)-(−)-beta-pinene-from-xtal-3D-balls.png
CAS number 127-91-3 YesY
PubChem 14896
ChemSpider 14198 YesY
KEGG C09882 YesY
ChEBI CHEBI:50025 YesY
Jmol-3D images Image 1
Molecular formula C10H16
Molar mass 136.23 g mol−1
Appearance Colourless liquid
Density 0.872 g/mL
R-phrases R10 R36 R37 R38
S-phrases S26 S36
NFPA 704
NFPA 704.svg
Flash point 36 °C; 97 °F; 309 K
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

beta-pinene (β-pinene) is a monoterpene, an organic compound found in plants. It is one of the two isomers of pinene, the other being α-pinene. It is colorless liquid soluble in alcohol, but not water. It has a woody-green pine-like smell.

This is one of the most abundant compounds released by forest trees.[1] If oxidized in air, the allylic products of the pinocarveol and myrtenol family prevail.[2]