Structure−Reactivity Relationships in Oxidative Carbon−Carbon Bond Forming Reactions: A Mild and Efficient Approach to Stereoselective Syntheses of 2,6-Disubstituted Tetrahydropyrones
作者:Lijun Wang、John R. Seiders、Paul E. Floreancig
DOI:10.1021/ja046125b
日期:2004.10.1
Homobenzylic ethers with pendent enol acetate nucleophiles undergo highly efficient cleavage reactions followed by 6-endo cyclizations to form 2,6-disubstituted tetrahydropyrones with excellent stereocontrol at room temperature in the presence of the mild oxidant ceric ammonium nitrate. Cyclizations proceed through either stabilized or nonstabilized oxocarbenium ions. Structure-reactivity relationships
在温和氧化剂硝酸铈铵的存在下,具有悬垂的烯醇乙酸酯亲核试剂的均苄基醚经历高效的裂解反应,然后进行 6-内环化,形成 2,6-二取代的四氢吡喃酮,在室温下具有出色的立体控制。环化通过稳定或不稳定的氧代碳鎓离子进行。提出了结构-反应性关系,为自由基阳离子裂解过程的设计提供预测指导。基于立体选择性路易斯酸介导的缩醛开环制备环化底物的独特序列已被开发用于合成适用于生物活性天然产物合成的复杂底物。