Stereochemistry of 14-hydroxy-β-caryophyllene and related compounds

Article abstract of DOI:10.1016/0040-4020(95)00104-G

The isomerization of β-caryophyllene (3), under treatment with SeO₂, is described. Chemical correlations, between 3 and 14-hydroxy-β-caryophyllene (6) from Juniperus oxycedrus, are established. High resolution ¹H NMR spectra and analysis by molecular mechanics of 3, 6 and 14-acetoxy-β-caryophyllene (7) indicate the existence of two conformational isomers, βα and ββ, in each compound. At 25°C, the βα conformer predominates in 3 and 7 but the ββ conformer predominates in 6. The higher percentage of 6ββ possibly derives from an intramolecular hydrogen bond. The treatment of 3, 6 and 7 with m-CPBA generates, in each case, two diastereomeric 4,5-epoxi-derivatives. The epoxides obtained from 6 have been isolated and analysed separately.