A unified synthetic strategy toward oroidin-derived alkaloids premised on a biosynthetic proposal
摘要:
Details of the evolution of a synthetic strategy toward the spirocyclic chlorocyclopentane core of oroidin-derived alkaloids, including the axinellamines and potentially adaptable to palau'amine, are described. A proposed refinement of the Kinnel-Scheuer biosynthetic proposal for palau'amine is posited. Studies undertaken to improve the regioselectivity and efficiency of a key Diels-Alder reaction utilizing a novel protecting group strategy, microwave chemistry, and other strategies are described. Further insights regarding the suitability of different protecting groups during the epoxidation/chlorination/ring contraction sequence are disclosed. Several interesting by-products from this reaction sequence are reported. These studies have led to a unified synthetic strategy to the axinellamines and palau'amine. (c) 2006 Elsevier Ltd. All rights reserved.
A Biomimetic Route for Construction of the [4+2] and [3+2] Core Skeletons of Dimeric Pyrrole–Imidazole Alkaloids and Asymmetric Synthesis of Ageliferins
作者:Xiao Wang、Xiaolei Wang、Xianghui Tan、Jianming Lu、Kevin W. Cormier、Zhiqiang Ma、Chuo Chen
DOI:10.1021/ja309172t
日期:2012.11.14
The pyrrole-imidazole alkaloids have fascinated chemists for decades because of their unique structures. The high nitrogen and halogen contents and the densely functionalized skeletons make their laboratory synthesis challenging. We describe herein an oxidative method for accessing the core skeletons of two classes of pyrrole-imidazole dimers. This synthetic strategy was inspired by the putative biosynthesis