The use of lithium (α-methylbenzyl)allylamide for the asymmetric synthesis of unsaturated β-amino acid derivatives
作者:Stephen G. Davies、David R. Fenwick、Osamu Ichihara
DOI:10.1016/s0957-4166(97)00470-9
日期:1997.10
The unsaturated β-amino acid derivatives (3R)-(E)-3-(N-tert-butoxy-carbonyl)aminohex-4-enoate and methyl (2S,3S)-3-(N-tert-butoxycarbonyl)-amino-2-hydroxyhex-4-enoate have been synthesised from lithium (S)-(α-methylbenzyl)allylamide and (E,E)-tert-butyl hex-2,4-dienoate. After a highly stereoselective conjugate addition of the lithium amide to the α,β-unsaturated ester, or a highly stereoselective
不饱和β氨基酸衍生物(3 - [R )- (ê)-3-(ñ -叔丁氧基羰基)氨基己-4-烯酸乙酯和甲基(2-小号,3小号)-3-(ñ -叔丁氧羰基(S)-(α-甲基苄基)烯丙基酰胺锂和(E,E)-叔丁基合成了)-氨基-2-羟基己基-4-烯酸酯-2,4-己二酸正丁酯。在将酰胺锂高度立体选择的共轭加成到α,β-不饱和酯上或高度立体选择性的共轭加成-亲电羟基化之后,加合物被脱甲酸酯化,并且所得仲胺转化为苯甲酰胺或恶唑烷酮。的Ñ - α -甲基苄基基团,然后用甲酸或使用溶解金属还原除去。这些脱保护程序使分子中的不饱和度保持完整。