Studies in terpenoids. Part 40. Synthesis of (±)-sydowic acid

Abstract

5-Methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)phenol (5a), a phenolic analogue of the naturally occurring curcumen ether (1), has been synthesised via 5-(2-hydroxy-4-methylphenyl)-5-oxopentanoic acid (3a). Oxidation with alkaline permanganate or treatment with N-bromosuccinimide of the acetate (5b) followed by hydrolysis gave (±)-sydowic acid [3-hydroxy-4-(2,6,6-trimethyltetrahydropyran-2-yl)benzoic acid](5c), a fungal metabolite isolated from Aspergillus sydowi.