Concise and diastereoselective approach to syn- and anti-N-tosyl-α-hydroxy β-amino acid derivatives
摘要:
The methyl diazoacetate and aryl (N-tosyl)imines can be transformed into syn or anti a-hydroxy P-amino esters with high diastereoselectivities in three steps: the base promoted nucleophilic condensation of the methyl diazoacetate and aryl (N-tosyl)imines to give beta-(N-tosyl)amino alpha-diazoesters, followed by oxidation with Oxoneo to generate alpha-oxo esters, which were reduced with NaBH4 to yield the anti-N-losyl-alpha-hydroxy beta-amino ester, or hydrogenated with Pd/C (10%) as the catalyst to yield corresponding syn isomer, both in high diastereoselectivity. (c) 2005 Elsevier Ltd. All rights reserved.
Stereoselective nucleophilic addition of chiral lithium enolates to (N-tosyl)imines: enantioselective synthesis of β-aryl-β-amino acid derivatives
作者:Zhihua Ma、Yonghua Zhao、Nan Jiang、Xianglin Jin、Jianbo Wang
DOI:10.1016/s0040-4039(02)00498-7
日期:2002.4
Nucleophilicaddition of the chiral lithium enolates of (S)-(−)-4-benzyl-2-oxazolidinone acetamide with N-tosyl arylaldehyde imines gives β-aryl-β-amino acid derivatives in good yields and excellent diastereoselectivity.