Asymmetric Catalysis by Vitamin B12: The isomerization of achiral cyclopropanes to optically active olefins
作者:Thomas Troxler、Rolf Scheffold
DOI:10.1002/hlca.19940770502
日期:1994.8.10
Achiral spiroactivated cyclopropanes are isomerized to optically active (R)-(cycloalk-2-enyl)-Meldrum's acids ( = (R)-5-(cycloalk-2-enyl)-2,2-dimethyl-1,3-dioxane-4,6-diones) in high yield and ee's up to 86% by catalytic amounts of cob(I)alamin in polar protic solvents.
非手性螺环活化的环丙烷被异构化为旋光性(R)-(环烷-2-烯基)-Meldrum酸(=(R)-5-(环烷-2-烯基)-2,2-二甲基-1,3-二恶烷-4,6-二酮),在极性质子溶剂中催化量的Cob(I)alamin的ee高达86%。