Hydroxynitrile lyase-catalyzed addition of HCN to 2- and 3-substituted cyclohexanones
作者:Christoph Kobler、Anja Bohrer、Franz Effenberger
DOI:10.1016/j.tet.2004.08.079
日期:2004.11
yielding cyanohydrins is strongly catalyzed by hydroxynitrile lyases (HNLs). With PaHNL from bitter almonds, the addition to 2-alkyl cyclohexanones 1b–g is highly (R)-selective, whereas the methyl compound 1a reacts (S)-selectively. With MeHNL from cassava, all 2-alkyl derivatives 1 react (S)-selectively. The catalytic activity of both PaHNL and MeHNL decreases with increasing size of the substituent
将HCN加到产生氰醇的单取代环己酮中是由羟腈裂解酶(HNL)强烈催化的。与苦杏仁中的PaHNL相比,2-烷基环己酮1b - g的添加具有很高的(R)选择性,而甲基化合物1a则具有(S)选择性反应。与木薯的MeHNL一起,所有的2-烷基衍生物1选择性地反应(S)。PaHNL和MeHNL的催化活性都随着底物1中取代基尺寸的增加而降低。HCN加成至2-烷氧基环己酮4和3-取代的环己酮6的非对映选择性但是,它只是适度的。合成氰醇的绝对构型由X-射线晶体学确定ö - p -bromobenzoyl衍生物。