The highly chemo- and enantioselective organocatalytic tandem reaction between N-carbamate-protected hydroxylamines and α,β-unsaturated aldehydes is presented. The reaction represents a unique entry for the asymmetric synthesis of 5-hydroxyisoxazolidines, oxazolidin-5-ones or γ-hydroxyamino alcohols in high yields and 90-99% ee. A procedure for the conversion of the oxazolidin-5-ones into the corresponding β-amino acids is also described.
本文介绍了N-
氨甲酸酯保护的
羟胺与α,β-不饱和醛之间高度
化学选择性和对映选择性的有机催化串联反应。该反应为5-羟基
异恶唑烷、
恶唑烷-5-酮或γ-羟
氨基醇的不对称合成提供了一条独特途径,产率高且对映体过量达90-99% ee。同时,还描述了将
恶唑烷-5-酮转化为相应β-
氨基酸的方法。