The Synthesis of Ventilone A

Abstract

2-Amino-3,6-dimethoxy-4,5-methylenedioxybenzoic acid (12) was prepared from 1,4-dimethoxy-2,3-methylenedioxybenzene (8) via the isatin (11). The benzyne generated from (12) was intercepted with 3-acetyl-2-ethoxy-4-[(4-methoxyphenoxy)methyl]furan (4) to give the naphthol (27), which on treatment with cericammonium nitrate gave the dimethyl ether of ventilone A(29). Demethylation with boron tribromide then affordedventilone A (1).