alkylation of epoxyketones (1), (4) from Poly-L-leucine catalysed asymmetric epoxidation of α,β-unsaturated ketones provides a short, stereocontrolled route to optically pure α,β-epoxy tertiary alcohols (2), (3). These epoxyalcohols undergo Payne rearrangement in mild Lewis acid conditions to give the isomeric α,β-epoxy secondary alcohols (5), (6). Alternatively, the epoxide may be opened up in a highly regio-
聚
L-亮氨酸催化α,β-不饱和酮的不对称环氧化反应制得的环氧酮(1),(4)的格利雅烷基化为光学纯的α,β-环氧叔醇(2),(3)提供了短的,立体控制的途径。这些环氧醇在温和的
路易斯酸条件下经历Payne重排,得到异构体α,β-环氧仲醇(5),(6)。备选地,可以以高度区域和立体特异性的方式开放
环氧化物,以得到多取代的1-
氯-2,3
-二醇(7),(8)。