Synthesis of (+/−) arthrographol

Abstract

A total synthesis of (+/−) arthrographol (1) in seven steps from vanillin is reported. Key steps in the synthesis are a single-step conversion of 5-allylvanillin (2) into the benzofuranmethanol 6, alkylation of the chloride 25 with the lithium anion of crotyl phenyl sulfide to give the sulfide 26, and formation of the 1(E),3(E)-1,3-pentadienyl side chain of arthrographol (1) via oxidation of the sulfide 26 and subsequent elimination of phenylsulfenic acid. The synthetic (+/−) arthrographol (1) inhibits the growth of Ophiostoma clavigerum (Robin.-Jeff. & Davids.) Harrington, the most pathogenic of the fungi associated with the blue stain disease of lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Key words: arthographol, alkylation, 2-butenyl phenyl sulfide, polyketide.