Synthesis of 2-Aminoimidazole-Based Alkaloids

描述（由申请人提供）：本研究计划具有双重性质。总体目标是开发简洁有效的合成方法，合成和技术上具有挑战性的2-氨基咪唑基海绵生物碱，称为oroidin生物碱。特别地，我们计划合成节苷脂（4）、二溴agelaspongin（6）、ageliferin（7）、帕劳'amine（9）、agelastatin D（12）和axinellamine（14）。总的来说，这些和其他结构相关的代谢物具有无数的有效生物学效应。这项研究奋进的一个重要目标是开发和验证这种结构新颖的天然产物的统一化学方法。所提出的方法和途径基本上不含保护基团，并以生物遗传学考虑为指导。合成计划要求开发将2-氨基咪唑转化为合成天然化合物的关键中间体的方法。这些中间体的制备以及随后分子重排的便利性往往会支持或否认生物发生假说。这些代谢物的多功能和有效的合成将为生物医学研究提供结构修饰或特异性标记的底物。此外，在这一领域开发的方法将应用于合成赤潮毒素，石房蛤毒素，gonyautoxin I和gonyautoxin IV。

DESCRIPTION (provided by applicant): The plan of this investigation is twofold in nature. The overall objective is to develop concise and efficient syntheses of synthetically and technically challenging 2-aminoimidazole based sponge alkaloids known as the oroidin alkaloids. In particular, we plan to synthesize sceptrin (4), dibromoagelaspongin (6), ageliferin (7), palau'amine (9), agelastatin D (12), and axinellamine (14). Collectively, these and other structurally related metabolites possess a myriad of potent biological effects. An important goal within this research endeavor is the development and validation of a unifying chemical approach to this structurally novel class of natural products. The proposed methods and routes are essentially devoid of protecting groups and are guided by biogenetic considerations. The synthetic plan calls for methods development for transforming 2- aminoimidazoles into key intermediates for the synthesis of the naturally occurring compounds. The preparation of these intermediates and the facility of the ensuing molecular rearrangements would tend to support or disclaim the biogenetic hypothesis. Versatile and efficient syntheses of these metabolites would provide access to structurally modified or specifically labeled substrates for biomedical research. In addition, the methods developed in this area will be applied to synthesis of the red-tide toxins, saxitoxin, gonyautoxin I and gonyautoxin IV.