Essential‐oil inspired synthetic libraries: synthesis, spectral and gas‐chromatographic properties of new fenchyl esters

Herein, the design, synthesis, and gas‐chromatographic and spectral characterization of a library of endo‐ and exo‐fenchyl esters (formate, acetate, propanoate, butanoate, isobutanoate, pentanoate, isopentanoate, 2‐methylbutanoate, hexanoate, heptanoate, octanoate, nonanoate, tiglate, angelate, senecioate and benzoate; 32 compounds in total) were described. 1D‐ and 2D–NMR experiments combined with 1H iterative full spin analysis and GIAO (gauge invariant atomic orbitals) computation of NMR chemical shifts and coupling constants for DFT‐calculated minimum energy conformations enabled a complete 1H–NMR assignment of the higher‐order signals of the fenchyl‐core protons. Library members, derivatives of a well‐known monoterpenol of economical importance, often encountered in essential oils (EOs), might potentially represent new (up to now undiscovered), or be classified as rare, natural products. The data summarized in this work should facilitate future EO analyses, especially those studies dealing with minor constituents. The benefits of the usage of (untargeted) metabolome‐inspired synthetic libraries in the analysis of EOs were discussed. Endo‐fenchol is a well‐known monoterpenol of economical importance, often encountered in essential oils (EOs). There is a lack of data on its esters: rare or even potentially up‐to‐now undiscovered natural products. The data summarized in this work (design, synthesis and characterization of a 32‐membered library of endo‐ and exo‐ fenchyl esters) should facilitate future EO analyses, especially those studies dealing with minor EO constituents.