Alphapinene

Alpha-pinene, also spelled alpha-pinene, is a bicyclic monoterpene and one of the most common terpenes found in nature. Its molecular formula is C10H16, and it is a major constituent of many essential oils, particularly those derived from pine resin and turpentine. It is chiefly responsible for the characteristic pine smell and is also present in smaller amounts in several other plant essential oils, including fir, spruce, citrus, and rosemary.

The compound occurs in two enantiomeric forms, (+)-α-pinene and (−)-α-pinene, which share a common bicyclic skeleton but differ in optical activity and odor notes. Both forms are volatile, insoluble in water, and relatively flammable. Alpha-pinene is naturally produced by resin-producing trees as part of their defense and communication chemistry and is widely harvested from pine-derived essential oils for industrial use.

In industry, alpha-pinene is obtained through distillation and purification of plant essential oils. It serves as a fragrance ingredient and a flavor additive, contributing to pine-like notes in perfumes and foods. It is also a versatile starting material in organic synthesis, used to produce a range of other terpenoids and fragrance compounds through oxidation, rearrangement, and hydrogenation reactions. Its role as a chemical intermediate underpins its value in the fragrance, flavor, and chemical manufacturing sectors.

Safety and regulatory aspects note that alpha-pinene is a volatile organic compound that can cause skin and eye irritation and may irritate the respiratory tract if inhaled in high concentrations. It is flammable and should be handled with appropriate precautions in industrial settings.