Electron-rich 2-Pyridones, III: Stereochemistry and Reactivity of Phenylsulfonyl- substituted 2-Azabicyclo[2.2.2]octan-6-ones
作者:Claus Herdeis、Claudia Hartke-Karger、Hermann Lotter
DOI:10.1002/ardp.19903231112
日期:——
[4+2]cycloaddition of electron‐rich 5‐benzyloxy‐2‐pyridone (1) with phenylvinyl sulfone furnished, after functional group transformation, 2 in a syn/anti ratio of 3/7. Deprotonation with LDA provided the thermodynamic stable 2a. The α‐sulfonyl carbanion can be alkylated to 4. During reductive desulfonylation complete epimerisation to 5 occured. Synthesis of 5b was also accomplished by conjugate addition
[4 + 2] 富电子 5-苄氧基-2-吡啶酮 (1) 与苯基乙烯基砜的环加成反应,官能团转化后,2 的顺/反比为 3/7。用 LDA 去质子化提供了热力学稳定的 2a。α-磺酰基碳负离子可以被烷基化为 4。在还原脱磺酰化过程中完全差向异构化为 5。5b 的合成也通过将乙基苯基磺酰基碳负离子与 11 共轭加成来完成。