Metabolites of bird's nest fungi. Part 6. The synthesis of (±)-cybullol and a new synthesis of (±)-geosmin

Abstract

The stereoselective transformation of 6,10-dimethyl-4-octal-3-one (8) to racemic cybullol (1), a metabolite of Cyathus bulleri Brodie, is reported. The transformation 4,10-dimethyl-4-octal-3-one to (±)-geosmin (15) is described. The results of the photosensitized [4 + 2] cycloaddition of oxygen to a number of 10-methyl-2,4-hexalins are discussed.