A Practical Synthesis of (<i>S</i>)-2-Cyclohexyl-2-phenylglycolic Acid via Organocatalytic Asymmetric Construction of a Tetrasubstituted Carbon Center
作者:Osamu Tokuda、Taichi Kano、Wei-Guo Gao、Tetsuya Ikemoto、Keiji Maruoka
DOI:10.1021/ol052164w
日期:2005.10.1
[reaction: see text] A concise and enantioselective synthesis of (S)-2-cyclohexyl-2-phenylglycolic acid as a key intermediate for (S)-oxybutynin is reported. The crucial asymmetric tetrasubstituted carbon center was constructed with excellent stereoselectivity through the proline-catalyzed direct asymmetric aldol reaction between cyclohexanone and ethyl phenylglyoxylate under mild conditions.
[反应:见正文]据报道,作为(S)-奥昔布宁的关键中间体的(S)-2-环己基-2-苯基乙醇酸的简明和对映选择性合成。在温和的条件下,通过脯氨酸催化的环己酮与苯乙醛酸乙酯之间的直接不对称羟醛醛缩合反应,可以构建出具有出色的立体选择性的至关重要的不对称四取代碳中心。