A Highly Stereoselective Diels–Alder Cycloaddition of Enones with Chiral Cyclic 2-Amidodienes Derived from Allenamides
作者:Li-Chao Fang、Richard P. Hsung、Zhi-Xiong Ma、William R. Presser
DOI:10.1021/ol402254p
日期:2013.9.20
Lewis acid promoted Diels-Alder cycloadditions of a series of de novo chiral cyclic 2-amidodienes are described. These cyclic 2-amidodienes are derived from chiral alpha-allyl allenamides via a sequence of E-selective 1,3-H shift and 6 pi-electron pericyclic ring closure. With enones serving as effective dienophiles, these cycloadditions can be highly diastereoselective depending upon the chiral amide substituent, thereby representing a facile entry to optically enriched [2.2.2]bicyclic manifolds.