Enantioselective Direct Intermolecular Aldol Reactions with Enantiotopic Group Selectivity and Dynamic Kinetic Resolution
作者:Dale E. Ward、Vishal Jheengut、Olukayode T. Akinnusi
DOI:10.1021/ol050195l
日期:2005.3.1
4-dioxa-8-thiaspiro[4.5]decane-6,10-dicarboxaldehyde proceed with dynamic kinetic resolution and give single adducts in good yields with excellent ee's. The high enantiotopic group selectivity results from the high intrinsic diastereoface selectivity of the aldehydes. These reactions significantly extend the scope of the enantioselective direct aldol reaction and constitute simple and efficient syntheses of
[反应:见正文]四氢-4H-吡喃酮与外消旋1,4-二氧杂-8-硫杂螺[4.5]癸烷-6-甲醛和内消旋/ dl 1,4-二氧杂-8的脯氨酸催化的羟醛反应-thiaspiro [4.5] decane-6,10-dibarboxaldehyde可进行动态动力学拆分,并以良好的ee收率获得高收率的单加合物。高对映体基团选择性是由于醛的高固有非对映异构体选择性所致。这些反应显着扩展了对映选择性直接醛醇缩合反应的范围,并且构成有用的四丙酸酯合成子的简单而有效的合成。