Concise and diastereoselective approach to syn- and anti-N-tosyl-α-hydroxy β-amino acid derivatives
作者:Yonghua Zhao、Nan Jiang、Shufeng Chen、Cheng Peng、Xiaomei Zhang、Yaping Zou、Shiwei Zhang、Jianbo Wang
DOI:10.1016/j.tet.2005.04.054
日期:2005.7
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.