Total syntheses of ert-conduramine A and ent-7-deoxypancratistatin
摘要:
The first total synthesis of the title alkaloid has been accomplished in fourteen steps form 1-bromo-4-iodobenzene or 1-fluoro-4-iodobenzene via chemoenzymatic production of the antipodal cis-diene diols 4. (C) 1999 Elsevier Science Ltd. All rights reserved.
Enantioselective Nitroso-Diels-Alder Reaction and Its Application for the Synthesis of (−)-Peracetylated Conduramine A-1
作者:Chandan Kumar Jana、Stefan Grimme、Armido Studer
DOI:10.1002/chem.200901331
日期:2009.9.14
CuI‐catalyzed enantioselective nitroso‐Diels–Alderreactions (NDA reactions) of 2‐nitrosopyridine with various dienes are presented. The [CuPF6(MeCN)4]/Walphos‐CF3 catalyst system is best suited to catalyze the NDA reaction of various dienes by using 2‐nitrosopyridine as a dienophile. In most of the cases studied, cycloadducts are obtained in quantitative yield with very good to excellent enantioselectivities
Advances in Siloxane-Based Coupling Reactions: Application of Palladium-Mediated Allyl-Aryl Coupling to the Synthesis of Pancratistatin Derivatives. The Formal Total Synthesis of (±)-7-Deoxypancratistatin
作者:Philip DeShong、Krupa H. Shukla
DOI:10.3987/com-12-s(n)35
日期:——
Palladium-mediated coupling of an allylic carbonate and an aryl siloxane has been applied to the formal total synthesis of 7-deoxypancratistatin and pancratistatin analogues. The key coupling reaction involved the use of a novel palladium olefin complex resulting in regio- and stereoselective arylation yielding a tetracyclic A-C ring intermediate. The observed regioselectivity of the coupling reaction was consistent with a model in which an unsymmetrical pi-allyl palladium complex was formed. Coupling of a variety of substituted phenyl siloxane derivatives was achieved using the new Pd(0) system to provide access to novel pancratistatin derivatives.