Total Synthesis of Lepadiformine Alkaloids using <i>N</i>-Boc α-Amino Nitriles as Trianion Synthons
作者:Matthew A. Perry、Matthew D. Morin、Brian W. Slafer、Scott D. Rychnovsky
DOI:10.1021/jo300161x
日期:2012.4.6
synthesized in an enantiomerically pure form using a reductive cyclization strategy. N-Boc α-amino nitriles were deprotonated and alkylated with enantiomerically pure dibromides to afford the first ring. The products were manipulated to introduce phosphate leaving groups, and subsequent reductive lithiation followed by intramolecular alkylation formed the second ring with high stereoselectivity. The third
Lepadiformine A、B 和 C 是使用还原环化策略以对映体纯形式合成的。N -Boc α-氨基腈被去质子化并用对映体纯二溴化物烷基化以提供第一个环。操纵产物以引入磷酸盐离去基团,随后的还原锂化和分子内烷基化形成具有高立体选择性的第二个环。第三个环是通过去保护的胺分子内置换甲磺酸盐形成的。Lepadiformine A 和 B 含有一个与胺相邻的羟甲基。使用 Polonovski-Potier 反应作为关键步骤,按顺序引入该附属物。合成策略具有立体选择性和收敛性,并证明了N的效用-Boc α-氨基腈作为生物碱合成的关键。