We report a non-biomimetic total synthesis of (+)-daphnepapytone A, an unprecedented member of the guaiane-derived sesquiterpenoids that displays moderate inhibitory activity against -glycosidase (IC50 = 159 ± 2.1 M) and possesses a highly strained bridging cyclobutane motif. Our de novo approach provided expedient access to the tetracyclic core of (+)-daphnepapytone A through an intramolecular allenyl thermal [2+2] cycloaddition and a Pauson–Khand reaction with a labile cyclobutane. Finally, a late-stage oxidation/reduction sequence delivered (+)-daphnepapytone A with striking chemoselectivity and excellent diastereoselectivity.

中文翻译：

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笼状倍半萜类化合物 （+）-水萜酮 A 的简明全合成

我们报道了 （+）-daphnepapytone A 的非仿生全合成，这是一种前所未有的愈创木脂衍生倍半萜类化合物，对 -糖苷酶表现出中等抑制活性 （IC50 = 159 ± 2.1 M） 并具有高度应变的桥接环丁烷基序。我们的从头方法通过分子内烯丙基热 [2+2] 环加成反应和与不稳定环丁烷的 Pauson-Khand 反应提供了对 （+）-daphnepapytone A 四环核心的权宜之计。最后，晚期氧化/还原序列递送 （+）-daphnepapytone A，具有显着的化学选择性和出色的非对映选择性。