Synthesis of Longifolene

Longifolene: Biosynthesis and Synthesis

Longifolene is a naturally occurring tricyclic sesquiterpene hydrocarbon whose molecular formula is C₁₅H₂₄, most commonly associated with pine trees and their derivatives. longifolene is also found in little amounts in the essential oils of plants like eucalyptus, juniper and pinewood smoke. Longifolene have asymmetric carbon which means it exists as enantiomers (non-superimposable mirror images). It is a pale yellow, oily liquid with a pine-like odor. It is used in the fragrance industry as a component of woody and floral odorants and as a fixative.

Biosynthesis of Longifolene

The biosynthesis of longifolene begins with farnesyl diphosphate by means of a cationic polycyclization. Loss of the pyrophosphate group and cyclization by the distal alkene gives intermediate. A 1,3-hydride shift leads to another intermediate, followed by two additional cyclizations. The final step is a 1,2-alkyl migration, resulting in the formation of the tricyclic longifolene structure.

Synthesis of Longifolene

Corey's Total Synthesis (1961)

E.J. Corey accomplished the first total synthesis of longifolene in 1961, using a 14-step linear sequence. This synthesis is notable for its strategic bond analysis and construction of the tricyclic core via a late-stage cyclization.

Source: Wikipedia