CHEMICAL PROOF OF ENANTIOMERIC (−)-LONGIBORNEOL

During the course of investigation on constituents of liver-worts, four sesquiterpenoids showing opposite rotation, (−)-longiborneol, (−)-α-longipinene, (−)-longifolene and (+)-α-himachalene, were isolated from a Japanese liverwort. By preparation of derivatives and application of physical methods the absolute configuration of (−)-longiborneol, the main component, was elucidated as an optical antipode (I) of (+)-longiborneol isolated from higher plants.