Total Synthesis of (-)-Fasicularin and (-)-Lepadiformine A Based on Zn-Mediated Allylation of Chiral<i>N</i>-<i>tert</i>-Butanesulfinyl Ketimine
作者:San-Lin Mei、Gang Zhao
DOI:10.1002/ejoc.200901422
日期:2010.3
The stereoselective total synthesis of fasicularin (1) and lepadiformine A (2) is described, which features the utilization of a Zn-mediated allylation of a chiral, aliphatic, N-tert-butanesulfinyl ketimine to construct the amino-substituted quaternary carbon center in good yield and with excellent diastereoselectivity. The azaspirocyclic scaffold was installed sequentially by a Sharpless dihydroxylation
描述了 fasicularin (1) 和lepadiformine A (2) 的立体选择性全合成,其特征是利用锌介导的手性脂肪族 N-叔丁烷亚磺酰基酮亚胺烯丙基化来构建氨基取代的季碳中心良好的收率和优异的非对映选择性。通过Sharpless二羟基化和内部环氧化物开环反应依次安装氮杂螺环支架,并将该支架进一步转化为通用中间体5。去除5的甲苯磺酰基(Ts)保护基团并使用Luche试剂还原胺化完成( ―)-fasicularin (1),同时使用 L-selectride 还原 5,将 Ts 基团脱保护,并通过分子内氨基醇环缩合反应完成 (―)-lepadiformine A (2) 的全合成。