| Summary: | Enantioseparation of the newly synthesized series of novel quinoline-2(1<i>H</i>)-one epoxide structures <i>rac</i>-<b>6a</b>–<b>c</b> and <i>rac</i>-<b>8a</b>–<b>c</b>, named marinoepoxides, is described. Marinoepoxide <i>rac</i>-<b>6a</b>, the key intermediate in the total synthesis of natural products marinoaziridines A and B, as well as their structural analogues, was synthesized by addition of the achiral ylide generated in situ from the sulfonium salt <b>5</b> or <b>7</b>, to the carbon-oxygen double bond of the corresponding quinoline-2(1<i>H</i>)-one-4-carbaldehyde <b>4a</b>–<b>c</b> in good yield. Separation of enantiomers of (±)-2,3,3-trisubstituted marinoepoxides <i>rac</i>-<b>6a</b>–<b>c</b> and (±)-<i>trans</i>-2,3-disubstituted marinoepoxides <i>rac</i>-<b>8a</b>–<b>c</b> was studied using two immobilized polysaccharide type chiral stationary phases (CSPs); <i>tris</i>-(3,5-dichlorophenylcarbamoyl)cellulose stationary phase (CHIRAL ART Cellulose-SC) and <i>tris-</i>(3,5-dimethylphenylcarbamoyl)amylose stationary phase (CHIRAL ART Amylose-SA). Enantioseparation conditions were explored by high-performance liquid chromatography (HPLC) using dimethyl carbonate/alcohol mixtures and <i>n</i>-hexane/ethanol (80/20, <i>v</i>/<i>v</i>) as mobile phase, and by supercritical fluid chromatography (SFC) using CO<sub>2</sub>/alcohol mixtures as mobile phase. In all examined racemates, enantioseparation was successfully achieved, but its efficiency largely depended on the structure of chiral selector and type/composition of the mobile phase.
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