Constituents of Boesenbergia pandurata (syn. Kaempferia pandurata): Isolation, Crystal Structure and Synthesis of (±)-Boesenbergin A

Abstract

Partly racemized pinostrobin and pinocembrin, together with 2′, 6′-dihydroxy-4′-methoxychalcone, cardamonin and a new chalcone (±)-boesenbergin A, have been isolated from Boesenbergia pandurata Schl. (syn. Kaempferia pandurata Roxb., Zingiberaceae). Spectroscopic studies and X-ray crystallographic analysis have established the structure (±)-(E)-1-[7′-hydroxy-5′-methoxy-2′-methyl- 2′-(4″-methylpent-3″-enyl)-2′H-chromen-8′-yl]-3-phenylprop-2-enone for boesenbergin A. A simple synthesis of boesenbergin A has been achieved and its acid-catalysed cyclization has been studied. © 1982 ASEG.