Synthesis of 4-Pyrones by Formal Hydration of 1,3-Diynones Promoted by 1,4-Addition of Piperidine
作者:Erandi Liyanage Perera、Daesung Lee
DOI:10.1021/acs.orglett.2c02914
日期:2022.9.30
A new approach for the synthesis of 4-pyrones with broader substrate scope and functional group tolerance is described. The reaction proceeds via an initial 1,4-addition by piperidine, followed by nitrogen-assisted 6-endo-dig cyclization and hydrolysis. 1,3-Diynones with nonenolizable electron-withdrawing ketones and nonpropargylic H provide relatively high yields. For substrates with particular R2
描述了一种合成具有更广泛底物范围和官能团耐受性的 4-吡喃酮的新方法。该反应通过哌啶的初始 1,4-加成,然后是氮辅助 6 -endo-dig环化和水解进行。具有非烯醇化吸电子酮和非炔丙基 H 的 1,3-二炔酮提供相对较高的产率。对于具有特定 R 2取代基的底物,分离出 1,4- 或 1,6-加合物,这表明 R 2取代基的空间和电子因素应该对 6 -endo-dig环化产生强烈影响。