Synthesis of Chelocardin, Amidochelocardin, Premithramycinon and Chromocyclin

该项目的目的是建立合成途径，以获得chelocardin(2)、氨基甲酰胆碱(3)、prethramycinon(5)和chromoclin(6/7)。这些天然产物的特征是有一个共同的骨架，它与已建立的四环素的不同之处在于C2处存在甲基酮，而C4处存在不同的构型。在扑尔敏(5)和色环素(6/7)的情况下，在第4位有酒精部分而不是胺。所有天然产物都表现出不同的生物活性，因此是医疗应用的宝贵起点。作为我们正在进行的由于微妙的结构变化而使天然产品的生物活性合理化的计划的一部分，我们首先需要获得这些化合物，并有可能根据自己的意愿改变结构。这样得到的化合物随后将用于目标识别研究。然而，该项目的目标是建立获得上述天然产品的综合途径。

The aim of this project is to establish synthetic access to chelocardin (2), carbamidochelocardin (3), premithramycinon (5) and chromocyclin (6/7). These natural products are characterized by a common backbone, which differs from established tetracyclins only due to the presence of a methyl ketone at C2, and a different configuration at C4. In the case of premithramycinon (5) and chromocyclin (6/7) at position 4 there is an alcohol moiety instead of the amine. All natural products exhibit different biological activities and are therefore valuable starting points for medical applications. As part of our ongoing program to rationalize the biological activities of natural products due to subtle structural changes, we firstly need access to these compounds and the possibility to alter the structures at our will. The so-obtained compounds will afterwards being used for target identification studies. However, the goal of this project is to establish synthetic access to the above mentioned natural products.