Terpenoid Chemistry. V. Preparation of Pure Humulene

Abstract

Humulene may be purified by recrystallization of the silver nitrate adduct, C₁₅H₂₄.2AgN0₃, followed by regeneration of the hydrocarbon by either steam distillation or treatment with aqueous ammonia solution. The pure hydrocarbon, isolated as 25 above from the essential oil of Agonis abnormis, has b.p. 123 °C/10 mm, [α]_D²⁵ ± 0.0°, n_D²⁵ 1.5015, and d₄²⁵ 0.8865.