Highly stereoselective double (R)-phenylglycinol-induced cyclocondensation reactions of symmetric aryl bis(oxoacids)
作者:Mercedes Amat、Carlos Arróniz、Elies Molins、Carmen Escolano、Joan Bosch
DOI:10.1039/c0ob00970a
日期:——
The double cyclocondensation of symmetric pyridyl bis(oxoacids) 2b and 3b with (R)-phenylglycinol stereoselectively gave access to bis-phenylglycinol-derived oxazolopyrrolidine 9 and oxazolopiperidone 10, respectively. Application of the stereocontrolled cyclocondensation reaction to phenyl bis-γ-oxoacid 4b provided 11, which was converted to the corresponding enantiopure di(pyrrolidinyl)benzene 22. The absolute configuration of the new stereogenic centers generated in the key cyclocondenstion step was unambiguously established by X-ray crystallographic analysis.
对称的吡啶双(羧酸) 2b 和 3b 与 (R)-苯基甘氨醇的双环凝聚反应以立体选择性方式生成了分别来源于双苯基甘氨醇的噁唑吡咯烷 9 和噁唑哌啶酮 10。将立体控制的环凝聚反应应用于苯基双-γ-羧酸 4b,得到了化合物 11,该化合物进一步转化为相应的外消旋二(吡咯烷基)苯 22。通过 X 射线晶体学分析,明确确定了在关键环凝聚步骤中生成的新立体中心的绝对构型。