Enantioselective Synthesis and Stereoselective Rearrangements of Enol Ester Epoxides
作者:Yuanming Zhu、Lianhe Shu、Yong Tu、Yian Shi
DOI:10.1021/jo001593z
日期:2001.3.1
Enol esters can be epoxidized with high enantioselectivities using the fructose-derived chiral ketone 1 as catalyst and Oxone as oxidant. A detailed study of enantiomerically enriched enol ester epoxides has revealed that the acid-catalyzed rearrangement can proceed through two distinct pathways, one with retention of configuration and the other with inversion. The competition between the two pathways
可以使用果糖衍生的手性酮1作为催化剂,以Oxone作为氧化剂,以高对映选择性对烯醇酯进行环氧化。对对映异构体富集的烯醇酯环氧化物的详细研究表明,酸催化的重排可以通过两个不同的途径进行,一个保留构型,另一个保留反转。两种途径之间的竞争高度依赖于酸催化剂的性质。强酸有利于保持构型,而弱酸有利于构型转化。在热条件下,这些环氧化物会随着构型的反转而高度立体选择性地重排。的α-酰氧基酮的对映异构体或者可以从烯醇酯环氧化物一种对映体通过反应条件的明智选择来形成。