𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Total Synthesis of the Alkaloid (±)-Aspidophytine Based on Carbonyl Ylide Cycloaddition Chemistry

✍ Scribed by José M. Mejía-Oneto; Albert Padwa

Publisher
John Wiley and Sons
Year
2008
Tongue
German
Weight
338 KB
Volume
91
Category
Article
ISSN
0018-019X

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The Rh^II^‐catalyzed cycloaddition cascade of an indolyl‐substituted α‐diazo imide was used for the total synthesis of the complex pentacyclic alkaloid (±)‐aspidophytine. Treatment of the resulting dipolar cycloadduct with BF~3~⋅OEt~2~ induces a domino fragmentation cascade. The reaction proceeds by an initial cleavage of the oxabicyclic ring and formation of a transient N‐acyl iminium ion which reacts further with the adjacent tert‐butyl ester and sets the required lactone ring present in aspidophytine. A three‐step sequence was then used to remove both the ester and OH groups. Subsequent functional group manipulations allowed for the high‐yielding conversion to (±)‐aspidophytine.

📜 SIMILAR VOLUMES

Total Synthesis of the Squalene Synthase
Total Synthesis of the Squalene Synthase Inhibitor Zaragozic Acid C by a Carbonyl Ylide Cycloaddition Strategy
✍ Seiichi Nakamura; Yuuki Hirata; Takahiro Kurosaki; Masahiro Anada; Osamu Kataoka 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 English ⚖ 149 KB 👁 2 views

The zaragozic acids and squalestatins, a novel family of fungal metabolites isolated and characterized by researchers at Merck [1] and Glaxo, [2] respectively, in 1992, are the most potent inhibitors of squalene synthase known to date. [3] Some members of this family have also demonstrated the abili

The Macrocyclic Spermidine Alkaloid (−)-
The Macrocyclic Spermidine Alkaloid (−)-(S)-Neoperiphylline: Revision of the Structure Based on the Total Synthesis
✍ Sergey A. Sergeyev; Manfred Hesse 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 German ⚖ 109 KB 👁 1 views

## Abstract The total synthesis of the two isomeric macrocyclic enamides **2** and **17** is described. The precursor **14** was synthesized by means of template‐assisted macrocyclization (__Scheme 2__). Isomerization of **14** in the presence of [Fe(CO)~5~] gave **2** and **17** (__Scheme 4__). St