A Novel Approach to the Synthesis of Taxol. A Synthesis of Optically Active 3,7-dibenzyloxy-4,8-di-<i>t</i>-butyl-dimethylsiloxy-5,5-dimethyl-6-<i>p</i>-methoxybenzyloxy-2-octanone by Way of Stereoselective Aldol Reactions
作者:Teruaki Mukaiyama、Isamu Shiina、Kaku Sakata、Takayuki Emura、Keitarou Seto、Masahiro Saitoh
DOI:10.1246/cl.1995.179
日期:1995.3
of diastereoselective aldol reaction between 4-benzyloxy-5-t-butyldimethylsiloxy-2,2-dimethyl-3-p-methoxy-benzyloxypentanal (3) and ketene silyl acetal 4 using MgBr2·OEt2 as a catalyst. The chiral pentanal 3 was synthesized either by asymmetric aldol reaction of both prochiral aldehyde 5 and ketene silyl acetal 4 using a chiral Lewis acid or by diastereoselective aldol reaction between the chiral aldehyde
光学活性 3,7-dibenzyloxy-4,8-di-t-butyldimethylsiloxy-5,5-dimethyl-6-p-methoxybenzyloxy-2-octanone (2) 已通过 4-benzyloxy- 之间的非对映选择性羟醛反应合成5-叔丁基二甲基甲硅烷氧基-2,2-二甲基-3-对甲氧基-苄氧基戊醛(3)和乙烯酮甲硅烷基缩醛4,以MgBr2·OEt2为催化剂。手性戊醛 3 是通过使用手性路易斯酸的前手性醛 5 和烯酮甲硅烷基缩醛 4 的不对称羟醛反应合成的,或者通过衍生自 L-丝氨酸的手性醛 6 和衍生自异丁酸甲酯的烯醇锂之间的非对映选择性羟醛反应合成的。