Fungal products. Part III. Structure of wortmannin and some hydrolysis products

Structure (II) is proposed for the fungal metabolite, wortmannin. The absolute stereochemistry is deduced except for that at C-1, which remains undefined. The structure of the previously described acid, C21H22O7, obtained by acidic degradation, is determined, together with structures of the products of hydrolysis by potassium carbonate and by potassium hydrogen carbonate.