A practical totalsynthesis of (±)-cermizine D and a formalsynthesis of (±)-cermizine C were achieved. The four-step totalsynthesis comprised mainly a Michael addition, a Weinreb amide-activated substitution and a sequence of ketalation/PtO2-catalysed dearomatisation/reductive amination reactions that resulted in ring closure in 13.7% overall yield. The formalsynthesis was accomplished in 29.7%
实现了 (±)-cermizine D 的实际全合成和 (±)-cermizine C 的正式合成。四步全合成主要包括迈克尔加成、Weinreb 酰胺活化取代和一系列缩酮化/PtO2 催化的脱芳构化/还原胺化反应,导致闭环,总产率为 13.7%。正式合成以29.7%的总产率完成。
Expedient Enantioselective Synthesis of Cermizine D
作者:Nagarathanam Veerasamy、Erik C. Carlson、Rich G. Carter
DOI:10.1021/ol300342n
日期:2012.3.16
An efficient enantioselective synthesis of cermizine D has been developed that exploits the use of a common intermediate to access over 85% of the carbon backbone. Key steps include an organocatalyzed heteroatom Michael addition, a diastereoselective alkylation with α-iodomethyl phenyl sulfide, a conjugate addition to a vinylsulfone species, and a sulfone coupling/desulfurization sequence to join
Two New<i>Lycopodium</i>Alkaloids from<i>Lycopodium obscurum</i>
作者:Ke Pan、Jian-Guang Luo、Ling-Yi Kong
DOI:10.1002/hlca.201200505
日期:2013.6
Two new Lycopodium alkaloids, (+)‐cermizine D N‐oxide (1) and (8β)‐8‐(acetyloxy)obscurumine A (2), along with five known compounds, were isolated from the crude alkaloid portion of Lycopodium obscurum. Their structures were elucidated on the basis of spectroscopic data and chemical correlation. All of these alkaloids were tested in an assay for acetylcholine esterase (AChE) inhibitory activity.
两个新的石松生物碱,(+) - cermizine d Ñ氧化物(1)和(8 β)-8-(乙酰氧基)obscurumine A(2)中,用5点已知的化合物一起,被从粗生物碱部分隔离玉柏。根据光谱数据和化学相关性阐明了它们的结构。所有这些生物碱均通过乙酰胆碱酯酶(AChE)抑制活性试验进行了测试。