Safrole is an organic compound with the formula CH2O2C6H3CH2CH=CH2. It is a colorless oily liquid, but impure samples will appear yellow. It is a member of the phenylpropanoid family of natural products found in plants such as sassafras. It exists in a small amount in many plants and is used as a natural antifeedant. [2] Ocotea pretiosa[3] growing in Brazil and Sassafras albidum[2] growing in eastern North America are the main natural sources of safrole. It has a typical "candy store" aroma.
It is a precursor to the synthetic insecticide synergist piperonyl butoxide, the spice piperonal made from isosafrole, and the pathogenic/endopathogenic substance MDMA.
Sassafras is extracted from a variety of plants, especially from the sassafras tree (Sassafras albidum) native to North America and the Japanese star anise (Illicium anisatum, known as shikimi in Japan). [4] In 1844, French chemist Édouard Saint-Èvre determined the empirical formula of safrole [5]. In 1869, French chemists Édouard Grimaux (1835-1900) and J. Ruotte studied and named safrole [6]. They observed its reaction with bromine, indicating the presence of allyl groups. [7] By 1884, German chemist Theodor Poleck (1821-1906) proposed that safrole was a derivative of benzene, with two oxygen atoms bonded to benzene to form an epoxide (cyclic ether). [8]
In 1885, Dutch chemist Johann Frederik Eijkman (1851-1915) studied shikimol, an essential oil extracted from Japanese star anise, and found that shikimol was oxidized to form piperic acid,[9] whose basic structure was determined in 1871 Years by the German chemist Wilhelm Rudolph Fittig (1835-1910) and his student, the American chemist Ira Remsen (1846-1927) [10] Therefore, Eijkman deduced the correct basic structure of shikimol. [11] He also noted that shikimol and safrole share the same empirical formula and other similar properties, so he thought they might be the same. [12] In 1886, Poleck showed that safrole also forms piperic acid upon oxidation, so shikimol and safrole are indeed the same. [13] Whether the C3H5 group of the molecule is propenyl (R-CH=CH-CH3) or allyl (R-CH2-CH=CH2) remains to be determined. In 1888, the German chemist Julius Wilhelm Brühl (1850-1911) identified the C3H5 group as an allyl group.
