<i>N</i>-Vinyl-2-oxazolidinones: Efficient Chiral Dienophiles for the [4 + 2]-Based de Novo Synthesis of New <i>N</i>-2-Deoxyglycosides
作者:Catherine Gaulon、Robert Dhal、Teddy Chapin、Vincent Maisonneuve、Gilles Dujardin
DOI:10.1021/jo040102y
日期:2004.6.1
Under smooth Eu(fod)3-catalyzed conditions, the inverse-electron demand hetero-Diels−Alder reactions between enantiopure N-vinyl-2-oxazolidinones 1a−f and representative β,γ-unsaturated α-ketoesters proceed with a high degree of endo and facial diastereoselectivity. The elucidation of the stereostructure of these adducts, performed by X-ray analysis or chemical correlation, shows that the endo-selective
在光滑的Eu(fod)3催化条件下,对映纯N-乙烯基-2-恶唑烷酮1a - f与代表性β,γ-不饱和α-酮酸酯之间的反电子需求异Diels-Alder反应以内部和面部非对映选择性。这些加合物的立体结构的阐明,通过X-射线分析或化学相关性,表明该内型选择性环加成方法是在有利于(2的脸部控制执行小号,4小号从(4开始时)-adduct小号)-dienophile,反之亦然。加合物的具体利益10A - Ë,来自(派生ē)-4-叔丁氧基亚甲基丙酮酸甲酯9可以通过将这些加合物分两步进行高度立体选择性转化为有价值的N -2-脱氧糖基-恶唑烷二酮12a - e,并通过纯非对映体分离得到。和对映体形式。