First syntheses of (-)-tauranin and antibiotic (-)-BE-40644 based on lipase-catalyzed optical resolution of albicanol.

First syntheses of sesquiterpene quinones (-)-tauranin and (-)-BE-40644 which exhibited strong cytotoxicity against several cancer cell lines, were achieved from (8aS)-albicanol obtained by enzymatic optical resolution. By comparison of the sign of specific rotation between synthetic (12bS)-BE-40644 and natural (-)-BE-40644, the absolute configurations of natural (-)-BE-40644 were determined to be 4aS, 6aS, 12aR, 12bS.