Stereoselective Intermolecular [4+2] Process of<i>N</i>,O‐acetals with Terminal Alkynes for Construction of Functional<i>cis</i>‐Pyrido and Pyrrolo[1,2‐c][1,3]oxazin‐1‐ones
作者:Chen Wang、Zhuo‐Ya Mao、Yi‐Wen Liu、Qiao‐E Wang、Chang‐Mei Si、Bang‐Guo Wei、Guo‐Qiang Lin
DOI:10.1002/adsc.201901141
日期:2020.2.21
A diastereoselective approach to access cis‐pyrido and pyrrolo[1,2‐c][1,3]oxazin‐1‐ones has been developed through a one‐pot BF3.Et2O‐catalyzed [4+2] process starting with N,O‐acetals and terminal alkynes. In addition, the utility of this transformation is demonstrated by the scalable synthesis of (+)‐Febrifugine in 7 steps from the N,O‐acetal (15% overall yield).
通过单锅BF 3开发了一种非对映选择性的方法来获得顺式吡啶基和吡咯并[1,2-c] [1,3]恶嗪-1-酮。从N,O-乙缩醛和末端炔烃开始的Et 2 O催化的[4 + 2]过程。此外,通过从N,O-乙缩醛分7步(总收率15%)的可扩展合成(+)-Febrifugine证明了这种转化的效用。