Preparation of leurosidine and novel leurosidine 4{40 -ethers and esters

摘要

Vincaleukoblastine (VLB, vinblastine) is converted to leurosidine, its 4' epimer, by reaction with thionyl chloride to form a bis-sulfite ester followed by treatment of the bis-sulfite ester with silver perchlorate. The bis-sulfite ester is covertible to novel 4' ethers by treatment with a lower alkanol or 4' esters of leurosidine perchlorate with acetic anhydride.