Tremorgenic Indole Alkaloids. Studies Directed toward the Assembly of the A, F, and I Rings of Penitrem D: Observation of an Unexpected Stereochemical Outcome
作者:Amos B. Smith、Naoki Kanoh、Noriaki Minakawa、Jon D. Rainier、Frances R. Blase、Richard A. Hartz
DOI:10.1021/ol9909379
日期:1999.10.1
critical for assembly of the A and F rings of penitrem D. We also explored simultaneous execution of this tactic with concurrent construction of ring I. Reinvestigation of a model system provided an explanation for the unanticipated stereochemical outcome at C(28).
Tremorgenic Indole Alkaloids. The Total Synthesis of (−)-Penitrem D
作者:Amos B. Smith、Naoki Kanoh、Haruaki Ishiyama、Noriaki Minakawa、Jon D. Rainier、Richard A. Hartz、Young Shin Cho、Haifeng Cui、William H. Moser
DOI:10.1021/ja034842k
日期:2003.7.1
A convergent, stereocontrolledtotal synthesis of the architecturally complex tremorgenic indole alkaloid (-)-penitrem D (4) has been achieved. Highlights of the synthesis include an efficient, asymmetric synthesis of the western hemisphere; the stereocontrolled assembly of the I-ring; discovery of a novel autoxidation to introduce the C(22) tertiary hydroxyl group, required for tremorgenic activity;
结构复杂的震颤吲哚生物碱 (-)-penitrem D (4) 的收敛、立体控制全合成已经实现。合成的亮点包括对西半球的高效、不对称合成;I形环的立体控制组装;发现了一种新的自动氧化,以引入震颤活动所需的 C(22) 叔羟基;充分阐述了东半球和西半球的联盟,利用专门为此目的制定的吲哚合成协议;以及利用 Sc(OTf)(3-) 促进的反应级联的 A 和 F 环的后期立体选择性构建。导致 (-)-penitrem D (4) 的最长线性序列为 43 步。
An end-game strategy for construction of the G-H-I rings of penitrem D, A tremorgenic indole alkaloid
作者:Amos B. Smith、Mitsuaki Ohta、William M. Clark、James W. Leahy
DOI:10.1016/s0040-4039(00)93371-9
日期:1993.5
synthetic approach to the G-H-I ring system of penitrem D has been developed in a model study. To generate the requisite carbon framework, the Stork protocol was utilized for coupling of a scalemic metalloenamine with an epoxide derived from D-glyceraldehyde. Pyran ring formation was then effected via BF3·OEt2-promoted cyclization of a δ-hydroxy allylic acetate.