Preparation of 7-Alkoxylated Furanopyrones:  Semisynthesis of (−)-Etharvensin, a New Styryl-Lactone from Goniothalamus arvensis

A new furanopyrone derivative, (−)-etharvensin (1), was isolated from the stem bark of Goniothalamus arvensis. Semisynthesis of the 7-ethoxyfuranopyrone 1 was achieved by addition of EtOH in concentrated acid medium to the unsaturated α-pyrone (+)-altholactone (2). This protocol constitutes a novel, direct (single-step), and efficient method to prepare this class of bioactive compounds.