An efficient synthesis of (±)-latifine dimethyl ether

Abstract

4,5-Dimethoxy-3-(4′-methoxyphenyl)phthalide (2) was hydrogenolysed to give 3,4-dimethoxy-2-(4′-methoxybenzyl)benzoic acid (3). The N-methylamide of (3) was lithiated and treated with dimethylformamide to furnish 3,4-dihydro-3-hydroxy-5,6-dimethoxy-4-(4′-methoxyphenyl)-2-methylisoquinolin-1(2H)-one (5). Reduction of compound (5) with lithium aluminium hydride gave (±)-latifine dimethyl ether (7).