Stereoselective synthesis of β-amino-α-fluoro esters via diastereoselective fluorination of enantiopure β-amino enolates
Stereoselective synthesis of β-amino-α-fluoro esters via diastereoselective fluorination of enantiopure β-amino enolates
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DOI：
10.1055/s-2004-817782
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发表时间：
2004-04-03
期刊：
影响因子：
2
通讯作者：
McCarthy, TD
中科院分区：
文献类型：
--
作者：
Andrews, PC;Bhaskar, V;McCarthy, TD
以肉桂酸t-丁酯和巴豆酸乙酯为原料，通过串联共轭加成(S)-(-)- n -苄基- n - α -甲基苄基酰胺，再与n -氟苯磺酰亚胺氟化，立体选择性地制备了-氨基-a-氟酯。x射线晶体学证实了各反应中形成的主要非对映体的绝对立体化学性质。完全脱保护，给予(2S,3S)- α -氟- β -苯丙氨酸，然后进行Fmoc保护。
beta-Amino-a-fluoro esters have been prepared stereoselectively from t-butyl cinnamate and ethyl crotonate via tandem conjugate addition of lithium (S)-(-)-N-benzyl-N-alpha-methylbenzylamide, followed by fluorination with N-fluorobenzenesulfonimide. The absolute stereochemistry of the major diastereomers formed in each reaction was confirmed by X-ray crystallography. Complete deprotection to give (2S,3S)-alpha-fluoro-beta-phenylalanine followed by Fmoc protection was achieved.