Stereostructure Reassignment and Determination of the Absolute Configuration of Pericosine D_o by a Synthetic Approach

A combination of chemical synthesis and NMR methods was used to reassign the structure of pericosine D_o (<b>8</b>), a cytotoxic marine natural product produced by the fungus <i>Periconia byssoides</i> OUPS-N133 that was originally derived from the sea hare <i>Aplysia kurodai</i>. Chemical synthesis was used to prepare pericoisne D_o (<b>8</b>) from a known chlorohydrin that was in turn derived from (−)-quinic acid. The absolute configuration of natural pericosine D_o (<b>8</b>) was determined to be methyl (3<i>R</i>,4<i>S</i>,5<i>S</i>,6<i>S</i>)<i>-</i>6-chloro-3,4,5-trihydroxy-1-cyclohexene-1-carboxylate. HPLC analyses using a chiral-phase column indicated that pericosine D_o (<b>8</b>) exists in an enantiomerically pure form in nature.