Iodide-Catalyzed Ring-Opening Cyclization of Cyclohexane-1,3-dione-2-spirocyclopropanes
作者:Hisanori Nambu、Yuta Onuki、Naoki Ono、Takayuki Yakura
DOI:10.1002/adsc.201800551
日期:2018.8.6
The ring‐opening cyclization of 2′,3′‐nonsubstituted and 2′‐electron‐withdrawing group (EWG)‐substituted cyclohexane‐1,3‐dione‐2‐spirocyclopropanes was accomplished using iodide as a catalyst. The nonsubstituted derivatives afforded 3,5,6,7‐tetrahydro‐1‐benzofuran‐4(2H)‐ones in high yields in the presence of trimethylsilyl iodide at room temperature. The EWG‐substituted spirocyclopropanes, in turn, underwent
2',3'-未取代和2'-吸电子基团(EWG)取代的环己烷-1,3-二酮-2-螺环丙烷的开环环化反应是使用碘化物作为催化剂进行的。在室温下,在存在三甲基甲硅烷基碘化物的情况下,未取代的衍生物可高收率提供3,5,6,7-四氢-1-苯并呋喃-4(2 H)-1 。然后,将EWG取代的螺环丙烷进行区域选择性的开环,然后进行环化,当使用碘化四丁基铵催化剂和三氟甲磺酸的组合时,生成2取代的四氢苯并呋喃-4-酮,而碘化钙则提供3取代基衍生品。