Illustrated Glossary of Organic Chemistry

Limonene: A terpene hydrocarbon natural product produced by many citrus species, named for its characteristic lemon/citrus odor. Natural sources produce a single enantiomer, which is (+)-limonene (the R enantiomer). IUPAC name: (R)-1-methyl-4-(1-methylethenyl)-cyclohexene.

Molecular structure of (R)-(+)-limonene.