Highly Diastereoselective Aldol Reactions with Camphor-Based Acetate Enolate Equivalents
作者:Claudio Palomo、Mikel Oiarbide、Jesús M. Aizpurua、Alberto González、Jesús M. García、Cristina Landa、Ibon Odriozola、Anthony Linden
DOI:10.1021/jo990865z
日期:1999.10.1
New lithium enolates of alpha-hydroxy ketones, derived from camphor, are evaluated for asymmetric aldol reactions in the presence of lithium chloride. The diastereoselectivity of the reactions between the lithium enolate of 3 and a variety of achiral aldehydes is strongly influenced by the lithium chloride salt. In these instances, the achieved levels of asymmetric induction, typically 95:5 dr, are
在氯化锂的存在下,对源自樟脑的新的α-羟基酮的烯醇锂进行了不对称羟醛反应的评估。氯化锂盐强烈影响3的烯醇锂和各种非手性醛之间反应的非对映选择性。在这些情况下,所达到的不对称诱导水平,通常为95:5 dr,在涉及甲基酮4的烯醇锂的羟醛反应中达到的范围内,这在空间上更加苛刻。所得的羟醛加合物容易转化为β-羟基羧酸,酮和醛,同时回收了樟脑,该方法的手性控制剂可以重复使用。