Fungal macrolides: Structure determination and biosynthesis of achaetolide,a lactone from Achaetomium cristalliferum

The structure of a new ten-membered lactone, achaetolide, isolated from cultures of Achaetomium cristalliferum is deduced from its mass and NMR spectra and from the study ofsomederivatives. The ¹³C NMR spectra of achaetolide enriched with 1-¹³C], 2-¹³C] and 1, 2-¹³C] acetate established its formation from eight intact acetate units via a precursor octaketide chain.