Stereoselective Formal Synthesis of (+)-Allokainic Acid <i>via</i> Thiol-Mediated Acyl Radical Cyclization
作者:Ken-ichi Yamada、Tomohiro Sato、Masaki Hosoi、Yasutomo Yamamoto、Kiyoshi Tomioka
DOI:10.1248/cpb.58.1511
日期:——
Stereoselective formal synthesis of (+)-allokainic acid was accomplished starting from L-glutamate by using a thiol-mediated acyl radical cyclization as a key step. The cyclization of a formylalkenoate proceeded in a highly diastereoselective manner to give trans-4,5-disubstituted pyrrolidin-3-one without the production of the cis-isomer. The pyrrolidinone was then converted into the established synthetic
通过使用巯基介导的酰基自由基环化作为关键步骤,从L-谷氨酸开始完成(+)-alkakainic酸的立体选择性形式合成。甲酰基链烯酸酯的环化以高度非对映选择性的方式进行,得到反式-4,5-二取代的吡咯烷-3--3-酮,而没有产生顺式异构体。然后,通过与异丙烯基格利雅试剂的铁催化的偶联反应,将吡咯烷酮转化为已建立的(+)-链烷酸的合成中间体。