Chiral ketones 1 and 2 bearing 1-aza-7-oxabicyclo[3.5.0]decane skeleton and their C2-symmetric analogue 3 were readily prepared and evaluated as a chiral dioxirane precursor for asymmetric epoxidation of olefins with Oxone®. The ketone 2, bearing a diphenyl steric wall, was not effective and gave quite poor selectivity. Good selectivity up to 83% ee was obtained using 1 and 3, which suggested that
易于制备带有1-
氮杂-7-
氧杂双环[3.5.0]
癸烷骨架的手性
酮1和2及其C 2对称类似物3,并将其评价为手性
二环氧乙烷前体,用于
烯烃不对称环
氧化。带有二
苯基立体壁的
酮2是无效的,并且选择性很差。使用1和3获得了高达83%ee的良好选择性,这表明羰基和醚
氧原子对库仑的排斥作用可作为电子壁而不是空间壁。