Asymmetric inverse electron-demand 1,3-dipolar cycloaddition of ynolates with a chiral nitrone derived from l-serine leading to β-amino acid derivatives
作者:Mitsuru Shindo、Keiko Ohtsuki、Kozo Shishido
DOI:10.1016/j.tetasy.2005.07.023
日期:2005.8
Asymmetric 1,3-dipolar cycloaddition of lithium ynolates with a nitrone derived from Garner’s aldehyde is described. The cycloadducts, 5-isoxazolidinones, were obtained in good yields with high diastereoselectivity. Alkylation of the intermediates, the 5-isoxazolidinone enolates, was also achieved with high selectivity, the products of which were converted into the enantiomerically pure β-amino acids
描述了炔醇锂与衍生自加纳醛的硝酮的不对称1,3-偶极环加成。以高收率和高非对映选择性获得环加合物5-异恶唑烷酮。还以高选择性实现了中间体5-异恶唑烷酮烯醇化物的烷基化,其产物被转化为对映体纯的β-氨基酸,β-内酰胺和γ-内酰胺。在我们的环加成反应中,与亲核锂相比,锂合成酸作为亲核试剂被证明要好得多。