Part I : Total synthesis and biological evaluation of antillatoxin and fragments Part II: Synthetic studies towards the total synthesis of cytochalasans and tuberostemonine

Abstract

In part I, the total synthesis of natural (4R, 5R)-antillatoxin and its analogue (4S, 5S)-antillatoxin has been achieved in 9 steps in 23% overall yield. Our strategy provides practical and easy entry into key intermediates and analogues. Screening utilizing zebrafish embryos of this library of simpler fragments obtained during the process of the total synthesis compounds has resulted in the discovery of bioactive fragments which display similar activity as (4R, 5R)-antillatoxin. These interesting results provide further evidence on the ease and usefulness of zebrafish embryos as a simple tool for fast biological evaluation in drug discovery research.In part II, the synthetic studies towards the total synthesis of cytochalasans and tuberostemonine have been carried out. Intermolecular Diels-Alder reaction was used as the key step in the construction of the six-membered core ring skeleton. We have successfully constructed the six-membered ring system for both molecules using BF3.OEt2 as the Lewis acid in dichloromethane at -78 A?C to -60 A?C.