Convenient Synthesis of 4-Methylenecyclobutenones and Their Synthetic Utility as Allenylketene Precursors
作者:Shigenobu Aoyagi、Kazuma Kikuchi、Kazuaki Shimada、Yuji Takikawa
DOI:10.1055/s-2007-986669
日期:2007.10
; Thermal reaction of alkynyl propargyl sulfides 1 in the presence of n-BuN 3 followed by moist silica gel treatment afforded 4-methylenecyclobutenones 4 in moderate yields. Photogeneration of allenylketenes 5 from 4 in the presence of amine or methanol gave 3,4-pentadienamides 6 or methyl 3,4-pentadienates 7, respectively. Similar reaction in the presence of aldimines afforded unsaturated δ-lactams
; 炔基炔丙基硫化物 1 在 n-BuN 3 存在下进行热反应,然后进行湿硅胶处理,以中等产率得到 4-亚甲基环丁烯酮 4。在胺或甲醇的存在下,从 4 光生成烯基烯酮 5 分别得到 3,4-戊二烯酰胺 6 或 3,4-戊二烯酸甲酯 7。在醛亚胺存在下的类似反应以良好的产率得到不饱和 δ-内酰胺 9。