A seven-step total synthesis of (+)-cylindricine D and epi-cylindricine D is described. The efficiency relies on the highly diastereoselective reductive bis-functionalization of N,O-protected (S)-pyroglutaminol by our recently improved protocol to build the N-α-tert-alkylamine motif, and a telescoped one-step four-reaction protocol to build the fused bicyclic ring system. (+)-Cylindricine C and its 2-epimer were synthesized by essentially the same sequence in eight steps. Acetylation of the latter then delivered (+)-cylindricine E and its 2-epimer, respectively.

中文翻译：

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海洋天然产物 (+)-柱状化合物 C、D、E 及其非对映体的对映选择性全合成

描述了 (+)-cylindricine D 和epi -cylindricine D 的七步全合成。效率依赖的高度非对映还原双官能N，O -保护（小号）-pyroglutaminol由我们的最近改进的协议来构建Ñ -α-叔烷基胺基序，和一个伸缩一步法四反应协议来构建稠合双环系统。(+)-Cylindricine C 和它的 2-差向异构体是按照基本相同的顺序分八步合成的。后者的乙酰化然后分别传递 (+)-cylindricine E 和它的 2-差向异构体。