Cross-over experiments unveil that the mechanism of the title reaction consists in cleavage of enol esters by cyanide with transient formation of acyl cyanides. These react as ‘soft’ C-acylating agents with the enolates freed in the initial step. Use is made of the acyl cyanide derived from pyrrole-2-carboxylic acid to set up the triketide type skeleton 12 of the antibiotic pyoluteorin 16. The aromatization
交叉实验揭示了标题反应的机理在于
氰化物裂解烯醇酯并短暂形成酰基
氰化物。这些作为“软” C-酰化剂与在初始步骤中释放出的烯醇化物反应。利用由
吡咯-2-羧酸衍生的酰基
氰化物来建立抗生素化脓性
叶黄素16的三酮化合物型骨架12。用
乙酸汞将12芳构化,得到
吡咯并[a]
吲哚酮18。