作者:Yohei Matsukawa、Minoru Isobe、Hiyoshizo Kotsuki、Yoshiyasu Ichikawa
DOI:10.1021/jo050407s
日期:2005.6.1
An efficient total synthesis of (+)-conagenin was achieved. The right fragment of conagenin, α-methylserine containing a quaternary stereocenter attached to nitrogen, was synthesized using allyl cyanate-to-isocyanate rearrangement. The left fragment, 2,4-dihydroxy-3-methylpentanoic acid, has three contiguous stereogenic centers, which was efficiently constructed by enantioselective monoreduction of
实现了(+)-刀豆蛋白的有效全合成。伴刀豆蛋白的右片段,即含有一个连接到氮原子上的四级立体中心的α-甲基丝氨酸,是利用氰酸烯丙酯到异氰酸酯的重排合成的。左片段2,4-二羟基-3-甲基戊酸具有三个连续的立体异构中心,这是通过Cossy报告的对映异构选择性单还原2-烷基-1,3-二酮和螯合控制的立体选择性还原β来有效构建的。 -羟基酮。这两个片段通过分子内酰胺键形成高效地偶联。