Superbase-Promoted Selective Cascade Cyclization Reaction of 1,5-Diketones with Acetylenes to Methylene-6,8-dioxabicyclo[3.2.1]octanes
作者:Elena Yu. Schmidt、Ivan A. Bidusenko、Nadezhda I. Protsuk、Igor A. Ushakov、Boris A. Trofimov
DOI:10.1002/ejoc.201201700
日期:2013.4
1,5-Diketones are readily cyclized in the presence of various alkali-metal superbases with acetylenes at 70 °C in a one-pot cascade reaction to give methylene-6,8-dioxabicyclo[3.2.1]octanes in up to 92 % yield. In the case of symmetrical 1,5-diketones, only one diastereomer is formed, whereas unsymmetrical diketones afford two diastereomers in a ratio corresponding to that of the starting ketones.
1,5-二酮在各种碱金属超强碱存在下与乙炔在 70 °C 的一锅级联反应中很容易环化,得到高达 92% 的亚甲基-6,8-二氧杂双环 [3.2.1] 辛烷屈服。在对称的 1,5-二酮的情况下,仅形成一种非对映异构体,而不对称的二酮以对应于起始酮的比例提供两种非对映异构体。该结果表明关键的级联环化序列是立体选择性的。
ZABOLOTNOVA T. V.; KAMINSKIJ V. A.; TILICHENKO M. N., XIMIYA GETEROTSIKL. SOEDIN., 1981, HO 4, 471-474
作者:ZABOLOTNOVA T. V.、 KAMINSKIJ V. A.、 TILICHENKO M. N.