Synthesis and Characterization of ε-Nonalactone

We sourced 2-nonanone, nonanoic acid and dichloromethane (98–99%) from Sigma-Aldrich, Taufkirchen, Germany. We synthesized ε-nonalactone in the laboratory following the method of Gikonyo et al. [9 (link)] as modified by Wachira et al. [21 (link)]. The ε-nonalactone synthesized consisted of a racemic mixture of equal quantities (50: 50) of (+) ε-nonalactone and (-) ε-nonalactone enantiomers as described by Wachira et al. [21 (link)].
We confirmed the structure of the resultant ε-nonalactone using spectra of the molecule generated from Infra-Red (IR) Spectrometer (Shimadzu, Kyoto, Japan), High Resolution Mass Spectrometer (HR-MS) (Jiangsu Skyray Instrument Co., Ltd., Kunshan, China), Proton (¹H- NMR) and Carbon-13 (¹³C-NMR) Nuclear Magnetic Resonance Spectrometer (Agilent Technologies, Inc., California, USA), as outlined by Skoog et al. [22 ].