SYNTHESIS OF UNIQUE BORACYCLIC SYSTEMS

中环和大环化合物的拟定合成的一般方面： 合成化学家面临的一个重要挑战是介质的构建 和大环系统。 本申请第1部分提出的是 我们设想的贡献是使用所谓的“硼模板 综合”。 建议：（A）评估下列物质的合成潜力： 通过硼氢化/羰基化或等效物形成双环碳硼烷 杂原子取代的三烯底物的方法。 (B)这个硼砂 然后将在影响碎片化的条件下进行处理（Grob）， 得到含有中等尺寸环的烯属杂环（硼= 杂原子）。 最后（C），通过 硼的替代，这些硼环将被调查。 倍半萜（Cefigorgo 1）全合成研究进展 铆接的立体化学。 使用“硼”的一个重要优点是 “模板”合成策略是有据可查和可预测的化学， 硼对聚烯烃的区域和立体选择性 印刷受体. 最重要的问题是， 羰基化立体化学的研究 (CO/氰化/碳负离子插入/等）。 为了解决这个问题，我们 提出通过硼环化合成pacifigorgo（缝合和 铆接），C-1羟基基团的立体化学从 铆接步骤。 根据现有的少量数据，我们 预测由环硼烷通过 羰基化或等效方法。 我们将探讨这种可能性， 铆接技术的变化可能会改变 硼置换过程。 这种全面综合的主要目标是 对碳硼置换过程有了更多的了解。

General aspects of proposed synthesis of Medium and Macrocyclic Compounds: An important challenge to synthetic chemists is the construction of medium and macrocyclic ring systems. Proposed in Part 1 of this application is our envisioned contribution using what is termed "Boron Template Synthesis". It is proposed to: (A) Assess the synthetic potential of forming bicyclic carboranes via hydroboration/carbonylation or equivalent process of heteroatom substituted triene substrates. (B) This boracycle will then be treated under conditions that effect fragmentation (Grob) to yield olefinic heterocycles containing a medium size ring (boron = heteroatom). Finally (C), the properties and synthetic utility, through replacement of Boron, of these boracycles will be investigated. Sesquiterpene (Pacifigorgo1) Total Synthesis: A Look at the Stereochemistry of Riveting. An important advantage in using the "Boron Template" synthetic strategy is the well documented and predictable chemo-, regio- and stereoselectivitiy of boron hydrides towards polyolefinic substrates. The overriding question which has generated this phase of our proposal deals with the stereochemistry of carbonylation (CO/cyanidation/carbanion insertion/etc.). To address this problem we propose the synthesis of pacifigorgo via Boron Annulation (stitching and riveting), the stereochemistry of the C-1 hydroxy1 group evolving from the riveting step. Based on the small amount of data available, we are predicting the formation of pacifigorgol from a boracyclane via carbonylation or equivalent process. We will explore the possibility that variations in riveting techniques might alter the stereochemical outcome of the boron replacement process. A major goal of this total synthesis is to present more insight into this carbon boron replacement process.