Diastereoselective total synthesis of (+)-morusimic acid B, an amino acid from Morus alba
作者:Marc E. Bouillon、Hartmut H. Meyer
DOI:10.1016/j.tet.2007.01.008
日期:2007.3
An efficient, flexible and diastereoselective synthesis of the naturally occurring pyrrolidine amino acid, (+)-morusimic acid B, has been accomplished. Starting from chiral, optically active (+)-(3S)-hydroxy butyric acid methyl ester the key steps of our synthesis are diastereoselective α-alkylation of its dianion to introduce the main part of the side chain, Curtius rearrangement of the hydrazide
已经完成了天然存在的吡咯烷氨基酸(+)-桑嘧啶酸B的有效,灵活和非对映选择性的合成。从手性旋光性(+)-(3 S)-羟基丁酸甲酯开始,我们合成的关键步骤是其二价阴离子的非对映选择性α-烷基化以引入侧链的主要部分,酰肼衍生物的库尔修斯重排生成2-恶唑烷酮,然后用乙酸汞(II)进行N →π-环化反应,生成顺式-2,5-二取代的吡咯烷环。远程C-3立体中心是在用乙酰乙酸甲酯的二价阴离子进行链延长并用Noyori's Ru(II)-(R)-BINAP催化剂。