Absolute configuration and total synthesis of (−)-cabenegrin A-I
作者:Adrienne L. Tőkés、György Litkei、Katalin Gulácsi、Sándor Antus、Eszter Baitz-Gács、Csaba Szántay、LászlóL. Darkó
DOI:10.1016/s0040-4020(99)00490-1
日期:1999.7
The total synthesis of (−)-cabenegrin A-I [(−)-1] in five steps was achieved from (−)-6aR,11aR-maackiain [(−)-5], which in turn was prepared by the optical resolution of racemic (±)-5 using S-(−)-α-methylbenzyl isocyanate as the the chiral auxiliary. The homochirality of (−)-maackiain [(−)-5] and (−)-cabenegrin A-I [(−)-1] was proved by CD measurements. Synthesis of (±)-maackiain [(±)-5] is also presented
由(-)-6a R,11a R -maackiain [(-)- 5 ]分五步完成(-)-benbenrin AI [[-]- 1 ]的全合成,然后通过光学方法制备(±)外消旋的分辨率- 5使用小号- ( - ) - α -甲基苄基异氰酸酯作为该手性助剂。通过CD测量证明了(-)-maackiain [(-)- 5 ]和(-)-cabenegrin AI [(-)- 1 ]的手性。(±)-maackiain [(±)-5的合成还从容易获得的酚衍生物间苯二酚和芝麻酚开始提出了[],这证明了Heck型氧化芳基化方法的合成效用,以克为单位获得了翼果烷衍生物。描述了一种新的翼果烷开环反应(7→28)。
Structures of cabenegrins A-I and A-II, potent anti-snake venoms
作者:Masashi Nakagawa、Koji Nakanishi、Laszlo L. Darko、James A. Vick