A strategy of highly stereoselective conjugate additions of lithium (R)-(α-methylbenzyl)benzylamide to tert-butyl cinnamate and its 2-methyl derivative combined with appropriate tandem or sequential electrophilic quenches allows the asymmetric syntheses of β-phenylalanine (95% enantiomeric excess) and homochiral (2R, 3S)- and (2S, 3S)-α-methyl-β-phenylalanine and the corresponding β-lactams (3R, 4S)- and (3S, 4S)-3-methyl-4-phenylazetidinones.
锂 (R)-(α-甲基苄基) 苄基酰胺的高度立体选择性共轭加成到
肉桂酸叔丁酯及其 2-甲基衍
生物的策略与适当的串联或顺序亲电猝灭相结合,允许不对称合成 β-苯丙
氨酸 (95%对映体过量)和纯手性(2R,3S)-和(2S, 3S)-α-甲基-β-苯丙
氨酸和相应的β-内酰胺(3R,4S)-和(3S,4S)-3-甲基-4-苯基氮杂
环丁酮。