NEW METHODS FOR STEREOSELECTIVE ADDITIONS TO CARBONYLS

羰基立体选择性加成的新方法

• 批准号: 2546019
• 负责人: TAREK SAMMAKIA
• 金额: $ 17.25万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 1999-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2546019
• 关键词: Diels Alder reaction; HMG coA reductases; alkyl group; carbonyl compound; catalyst; chemical addition; chemical synthesis; enzyme inhibitors; hydroxyl group; ketal; stereochemistry

DESCRIPTION: The principal investigator notes that he is engaged in a research program, the aims of which are to discover new stereoselective and chemoselective reactions and reagents in organic synthesis. He states that he uses the tools of mechanistic organic chemistry to uncover the origin of asymmetric induction in reactions that proceed with high levels of selectivity, then uses these results as a guide in the investigation of new reactions that exhibit similar levels of stereoselectivity. The principal investigator indicates that he is continuing to study the mechanism of Lewis acid mediated nucleophilic additions to acetals and that he has developed a method which allows him to determine the level of stereospecificity in these reactions and thereby distinguish between an SN1 and an SN2 mechanism. It is noted that in this proposal, a related method is described that is being applied to chiral acyclic acetals. These substrates were said to have been chosen because they display an unusual stereochemical dependence on the nature of the alkyl group of the acetal. These mechanistic studies are noted to have led the principal investigator to explore new methods for achieving remote asymmetric induction in the Diels-Alder reaction via chiral vinyl oxocarbenium ions. He indicates that he is extending this to intramolecular Diels-Alder reactions and that this method is also being applied to the synthesis of the HMG-CoA reductase inhibitor dihydrocompactin.

描述：主要研究者指出，他从事一项 研究计划，其目的是发现新的立体选择性 以及有机合成中的化学选择性反应和试剂。 他 他使用机械有机化学的工具来揭示 在高浓度下进行反应中不对称诱导的起源 选择性水平，然后使用这些结果作为指导， 研究显示出类似水平的新反应 立体选择性 首席研究员表示，他是 继续研究刘易斯酸介导的亲核反应机理 添加到缩醛，他已经开发出一种方法，使他 以确定这些反应中的立体特异性水平， 从而区分SN 1和SN 2机制。 应注意 在本提案中，描述了一种相关方法， 应用于手性无环缩醛。 据说这些基质具有 之所以被选中，是因为它们显示出对 缩醛的烷基的性质。 这些机械研究 导致首席研究员探索新的方法 为了在Diels-Alder反应中实现远程不对称诱导， 手性乙烯基氧碳正离子。 他表示，他正在扩大这一 分子内Diels-Alder反应，并且该方法也 应用于HMG-CoA还原酶抑制剂的合成， 二氢康帕汀