Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
Org Lett. 2009 Dec 17;11(24):5642-5. doi: 10.1021/ol902326s.
A palladium-catalyzed decarboxylative [4 + 3] cyclization of gamma-methylidene-delta-valerolactones with 1,1-dicyanocyclopropanes has been developed to produce cycloheptane derivatives in a convergent manner. This method can be applied to the synthesis of azepanes by reacting with aziridines, and their asymmetric variants have also been described. In addition, selective ring-expansion reactions can be achieved for certain gamma-methylidene-delta-valerolactones to give nondecarboxylated nine-membered lactones.
钯催化γ-亚甲基-δ-戊内酯与 1,1-二氰基环丙烷的脱羧[4 + 3]环化反应以收敛方式生成环庚烷衍生物。该方法可通过与氮丙啶反应应用于氮杂环庚烷的合成,并且还描述了它们的不对称变体。此外,对于某些γ-亚甲基-δ-戊内酯,可以通过选择性的环扩张反应得到非脱羧的九元内酯。