Determination of the Absolute Configuration of Synerazol

Synerazol (1) was originally isolated as an antifungal antibiotic from Aspergillus fumigatus1). 1 possesses an epoxy functionality instead of the 1,2-dihydroxyl group in pseurotin A (2), the first identified member of this class of secondary metabolites.While the absolute configuration of 2 was determined by X-ray diffraction2), the stereochemistry of 1 remains to be solved.We recently found that fluorinated analogs of synerazol, produced by the precursor-directed biosynthesis using fluorophenylalanines, show potent antiangiogenic activity3).Since pseurotin analogs do not show such activities, the epoxy moiety is considered important.A. fumigatus TP-F0182 produces both 1 and 2 in a liquid