Abstract: Brefeldin-A, an antibiotic fungal metabolite, has been obtained in both racemic and natural forms through a direct approach that employs norbornenone and 6-heptyn-2-01 as the basic starting materials. ... Brefeldin-A (as decumbin) was first isolated in 1958 from Penicillium decumbens by Singleton, Bohonos, and Ullstrup.la The metabolite has subsequently been found in cultures of Pen- icillium cyaneum,lb Penicillium brefeldianum,lc and Ascochyta ...