Graduate School of Pharmaceutical Sciences , Kyoto University , Yoshida, Sakyo-ku, Kyoto 606-8501 , Japan.
Org Lett. 2019 Sep 20;21(18):7563-7567. doi: 10.1021/acs.orglett.9b02835. Epub 2019 Sep 9.
We report herein the development of an acid-promoted rearrangement of oxa[4.3.2]propellanes to afford polyaromatic-fused spiro[4.5]carbocycles. DFT calculations suggest that the reaction pathway involves generation of a cyclobutyl cation, ring contraction to the cyclopropylcarbinyl cation, and dearomative ring closure by an internal 2-naphthol moiety. The resulting spirocarbocycles are synthetically valuable, as they could be transformed into two different polycyclic aromatic hydrocarbons via skeletal rearrangement. Syntheses of optically pure spirocarbocycles via a central-to-axial-to-central chirality transfer are also described.
我们在此报告了一种酸促进的 oxa[4.3.2]propellanes 的重排反应，以提供稠合多环芳烃的螺[4.5]碳环体系。DFT 计算表明，反应途径涉及环丁基阳离子的生成、环丙基碳正离子的环收缩以及内部 2-萘酚部分的去芳构化环闭合。所得的螺环碳环体系具有合成价值，因为它们可以通过骨架重排转化为两种不同的多环芳烃。通过中心-轴向-中心手性转移的光学纯螺环碳环的合成也有描述。
