Enantioselective Generation and Diastereoselective Reactions of Chiral Enolates Derived from ?-Heterosubstituted Carboxylic Acids. Preliminary Communication
作者:Dieter Seebach、Reto Naef
DOI:10.1002/hlca.19810640829
日期:1981.12.16
Dioxolanones 7 and 8a and oxazolinones 9a derived from pivalaldehyde and lactic acid, mandelic acid, and proline, respectively, furnish chiral enolates of type 3 by deprotonation with LDA. Reactions of these enolates with alkyl halides, aldehydes, and ketones ( 8b, 9b, 11–13) are highly diastereoselective. Thus, the overall enantioselective α-alkylation of chiral, non-racemic α-heterosubstituted carboxylic
分别衍生自新戊醛和乳酸,扁桃酸和脯氨酸的二氧戊环酮7和8a以及恶唑啉酮9a通过用LDA脱质子化提供3型手性烯醇化物。这些烯醇化物与烷基卤化物,醛和酮(8b,9b,11-13)的反应具有很高的非对映选择性。因此,实现了手性的,非外消旋的α-杂取代的羧酸(4-6)的整体对映选择性α-烷基化。