Synthesis of 2-azaspiro[4.4]nonan-1-ones via phosphine-catalysed [3+2]-cycloadditions
作者:Sarah R. Yong、Morwenna C. Williams、Stephen G. Pyne、Alison T. Ung、Brian W. Skelton、Allan H. White、Peter Turner
DOI:10.1016/j.tet.2005.06.050
日期:2005.8
2-methylene γ-lactams 4 and 5 and the acrylate 6 with the ylides derived from the ethyl ester, the amide or the chiral camphor sultam derivative of 2-butynoic acid (7a–c) give directly, or indirectly after reductive cyclization, spiro-heterocyclic products. The acid 32 underwent Curtius rearrangement and then acid hydrolysis to give two novel spiro-cyclic ketones, 41 and 42.
2-亚甲基γ-内酰胺4和5和丙烯酸酯6的膦催化[3 + 2]-环加成反应,生成的酰基化物衍生自2-丁酸的乙酯,酰胺或手性樟脑磺酰胺衍生物(7a – c)在还原环化后直接或间接产生螺杂环产物。酸32进行Curtius重排,然后酸水解得到两个新的螺环酮41和42。