Asymmetric synthesis of cryptofolione and determination of its absolute configuration

Abstract

Two possible stereoisomers of cryptofolione, isolated from the Cryptocarya species in South Africa and Brazil, were synthesized in an enantioselective manner by using asymmetric hetero Diels-Alder reaction as the key steps. Comparative evaluation of the 1H NMR, 13C NMR, CD spectra, and specific rotation of the synthetic compounds with those reported in the literature was performed to establish the absolute configuration of cryptofolione to be [6R,10S,12R]. © 2005 The Japan Institute of Heterocyclic Chemistry.