ASYMMETRIC SYNTHESIS OF BIOLOGICALLY IMPORTANT ALKALOIDS

我们建议进一步开发，完善和测试新的方法， 许多杂环化合物在氮的α位立体选择性烷基化 提供生物碱和其它胺的系统， 光学产率 这些方法中有几种是前所未有的， 获得重要的化合物类别，因为它们具有独特的 结构特征和/或其在化学中的关键作用， 生物化学 新的偶极稳定的阴离子前体将是 研究作为潜在有用的合成工具，在非循环 立体选择 异吲哚啉的不对称α，α ′-二烷基化提供了获得 一类独特的具有C2对称性的手性2度胺。 使用 这些2度胺作为对映选择性碱也将被研究， 以及它们在几种其它不对称方法中作为手性助剂的用途。 我们 建议评估其他氨基恶唑啉作为手性佐剂， 继续努力阐明不对称诱导的机制， 偶极稳定的阴离子体系。

We propose to further develop, refine, and test new methods for the stereoselective alkylation, alpha to nitrogen, of a number of heterocyclic systems affording alkaloids and other amines in excellent chemical and optical yields. Several of these methods are unprecedented, and all afford access to classes of compounds which are important because of their unique structural features and /or their pivotal role in chemistry and biochemistry. The new dipole-stabilized anion precursors will be investigated as potentially useful synthetic tools in acyclic stereoselection. The asymmetric alpha, alpha'-dialkylation of isoindoline affords access to a unique class of chiral 2 degree amines having C2 -symmetry. The use of these 2 degree amines as enantioselective bases will be examined, as well as their use as chiral adjuvants in several other asymmetric processes. We propose to evaluate other aminooxazolines as chiral adjuvants, and to continue our efforts to elucidate the mechanism of asymmetric induction in dipole-stabilized anion systems.