Synthesis of sesquiterpene derivatives as potential antitumor agents; Elemane derivatives

Derivatives of elema-1,3-diene were synthesized in several steps as polar a nalogs of beta-elemene, antitumor agent under clinical phase. The lactone r ing of compound 1 was opened by LiAlH4 to give diol 2 which was selectively protected by TBDPSCl. After acetylation of the secondary alcohol, the acet ylated product was ozonolyzed and reduced to give elemane derivative 4 whic h was converted to diolefin 8 via selenides subsequent deprotection by tetr abutylammonium fluoride gave two compounds 9, 10.