Absolute Configuration of the Fungal Metabolite Spirolaxine

Abstract The relative stereochemistry of the four stereocentres of spirolaxine 1, a bioactive 6,5‐spiroacetal phthalide secondary metabolite, was determined through single‐crystal X‐ray analysis. Its absolute configuration was determined by circular dichroism; the experimental spectrum of spirolaxine is in good agreement with that evaluated by means of DeVoe coupled‐oscillator calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)