In Western Australia, Boronia ternata Endl is an exception among Boronia species (Rutaceae) that occurs in arid and semi-arid regions, prompting a preliminary examination of its constituents. Ether extraction of leaves yielded an alkaloid mixture containing 1-acetoxymethyl-2-n-propyl-4-quinolone (C15H17NO3) and skimmianine. The structure of 1-acetoxymethyl-2-n-propyl-4-quinolone was confirmed by infrared (ester at 1740 cm-1, conjugated carbonyl at 1640 cm-1), ultraviolet, and 60 Mc/s nuclear magnetic resonance (n.m.r.) spectra, which revealed acetoxymethyl, propyl, and quinolone moieties. Methanol extraction produced 2-n-propyl-4-quinolone (C12H13NO), identified as an artifact from 1-acetoxymethyl-2-n-propyl-4-quinolone via alkali (yielding formaldehyde, acetic acid, and the artifact) or hydrogen chloride treatment. The occurrence of 2-n-propyl-4-quinolone completes the series of odd-numbered homologous chains (up to undecyl) in Rutaceae alkaloids, consistent with biogenesis via anthranilic ester and β-ketoacid as proposed by Cornforth and James.