| 摘要 |
5-Amino-4-oxo-pentanoic acids of the formula <IMAGE> wherein R is CF3, CHF2 or CH2F; R1 is H or akyl of 1-4 carbon atoms; and R2 is H or alkyl or 1-4 carbon atoms or benzyl, which are intermediates to ACE inhibitors or elastase inhibitors, are produced by reacting a 1-(methylthio)-1-methylsulfinyl)-2-R1-ethylmetal with an ester of a 3-R-acrylic acid; optionally R2-alkylating the thus-produced ester enolate anion of 4-(methylsulfinyl)-4-(methylthio)-5-R1R-pentanoic acid followed by splitting off of methylsulfinic acid; reacting the thus-produced 2-R2-5-R1-4-(methylthio)-3-R-4-pentenoic acid ester with a source of Br+ to produce a 5-bromo-substituted acid or ester thereof otherwise corresponding to the desired 5-amino-4-oxo-pentanoic acid; and replacing the bromine atom with an amino group, e.g., via the corresponding 5-azido- and 5-N-acylamino- compounds, with hydrolysis of the ester group, if still remaining.
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