Eleganketal a, a highly oxygenated dibenzospiroketal from the marine-derived fungus Spicaria elegans KLA03

Eleganketal A (1), a naturally occurring aromatic polyketide possessing a rare highly oxygenated spiro[isobenzofuran-1,3′-isochroman] ring system, was isolated from the fungus Spicaria elegans KLA03 by culturing it in a modified mannitol-based medium. The structure of 1 including the absolute configuration was determined by combining spectroscopic analysis, synthesis of the racemic permethylated analogue, chiral-phase HPLC separation, and TDDFT-ECD analysis.