Synthesis of Polyketides and Terpenes

描述（由申请人提供）：这项正在进行的拟议研究的目的是为合成具有临床显著生物活性的复杂天然物质做出创造性贡献。该资助将继续开发新的立体选择性反应，并将该方法应用于复杂聚酮抗生素和抗微生物剂的不对称合成。合成目标将包括amphinidinol 3、aflastatin 3、（+）peloruside A、salvinorin A、佛波醇和四环素家族抗生素。一个重要的新方法，在合成多环结构的无环前体已被说明在设计salvinorin A，佛波醇，四环素。所有这些合成开始与键的结构，立体化学调控的无环立体控制。然后通过一系列分子内、跨环过程从中环大环组装碳骨架。沿着多核苷酸、肽和多糖，聚酮化合物代表由共同亚基组装的天然存在的材料的第四大家族。在扩展与肽合成的比较中，通过复杂的羟醛键结构的聚酮组装是比类似的肽片段组装类比大得多的挑战，因为在片段偶联事件期间产生多达两个新的立体中心。我们这项资助的长期目标是开发组装聚酮衍生天然产品的所有方法。这一目标包括手性烯醇化物方法学的发展，羰基和烯醇化物π-面选择性的远程立体中心的研究，和双立体分化羟醛加成反应的预测模型的发展。目标是提高反应设计的可预测性。聚酮化合物的靶点是amphidinol A、aflastatin 3、peloruside和salvinorin A。化学合成提供了生产化疗药物的能力，化学反应是从事药物发现过程的药物化学家不可替代的工具。化学反应技术的进步缩短了作为潜在候选药物的化学实体的概念与其合成用于随后的生物学评价之间的间隔。因此，有机合成是一门重要的学科，继续对医学和生物学领域产生重要影响。

DESCRIPTION (provided by applicant): The objectives of this ongoing proposed research are to make creative contributions to the synthesis of complex naturally occurring substances possessing clinically significant biological activity. This grant will continue to develop new stereoselective reactions and the application of this methodology to the asymmetric synthesis of complex polyketide antibiotics and antineoplastic agents. The synthesis targets will include amphinidinol 3, aflastatin 3, (+) peloruside A, salvinorin A, phorbol, and the tetracycline family of antibiotics. An important new approach in the synthesis of polycyclic structures from acyclic precursors has been illustrated in the design of salvinorin A, phorbol, and tetracycline. All of these syntheses begin with bond constructions that are stereochemically regulated by acyclic stereocontrol. The carbon framework is then assembled by a series of intramolecular, transannular processes from medium-ring macrocycles. Along with polynucleotides, peptides, and polysaccharides, polyketides represent the fourth broad family of naturally occurring materials that are assembled from common subunits. In extending the comparison with peptide synthesis, polyketide assembly through complex aldol bond constructions is a far greater challenge that the analogous peptide fragment assembly analogy since up to two new stereocenters are created during the fragment coupling event. Our long term objective in this grant has been the development of all of the methodology to assemble polyketide-derived natural products. This objective includes the development of chiral enolate methodology, the study of remote stereocenters on carbonyl and enolate pi-face selectivities, and the development of predictive models for double stereodifferentiating aldol addition reactions. The goal is to improve reaction design predictability. The polyketide targets are amphidinol A, aflastatin 3, peloruside, and salvinorin A. Chemical synthesis provides the capacity to produce chemotherapeutic agents, and chemical reactions are the irreplaceable tools of the medicinal chemist engaged in the drug discovery process. Advances in chemical reaction technology reduce the interval between the conception of the chemical entity as a potential drug candidate and its synthesis for subsequent biological evaluation. As a consequence, organic synthesis is a critical discipline that continues to have an important impact on the fields of both medicine and biology.