Schmidt Elena Yu, Bidusenko Ivan A, Protsuk Nadezhda I, Ushakov Igor A, Trofimov Boris A
A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, 1 Favorsky Str., 664033 Irkutsk, Russia.
Org Biomol Chem. 2023 Apr 12;21(15):3183-3202. doi: 10.1039/d3ob00252g.
2-Acetyl-3,4-dihydropyrans, assembled from acetylene gas and ketones in a one-pot procedure, are ethynylated with acetylenes (KOBu/DMSO, 15 °C, 2 h) to give acetylenic alcohols, which readily cyclize (TFA, rt, 5 min) to 7-ethynyl-6,8-dioxabicyclo[3.2.1]octanes in up to 92% yield. The ring closure of the above acetylenic alcohols can be performed without their isolation from the reaction mixture. Thus, the synthesis of 7-ethynyl-6,8-dioxabicyclo[3.2.1]octanes can be realized in just two synthetic operations from simple and available starting materials under mild transition-metal-free conditions.
由乙炔气体和酮通过一锅法组装而成的2-乙酰基-3,4-二氢吡喃，在乙炔存在下（叔丁醇钾/二甲基亚砜，15℃，2小时）进行乙炔基化反应，生成炔醇，该炔醇能迅速环化（三氟乙酸，室温，5分钟），以高达92%的产率生成7-乙炔基-6,8-二氧杂双环[3.2.1]辛烷。上述炔醇的环化反应无需从反应混合物中分离出来即可进行。因此，在温和的无过渡金属条件下，仅通过两步合成操作，就能从简单易得的起始原料实现7-乙炔基-6,8-二氧杂双环[3.2.1]辛烷的合成。
