| 摘要 |
Peptide derivs. of 2N-(1-ethoxycarbonyl) 3-phenyl propyl alanine are made by (a) bromination of 4-phenyl butyric acid with Br2 in presence of PCl3 to give the racemic alpha-bromo acid; (b) chlorination to the acid chloride; (c) esterification with ethanol; (d) treatment with L-alanine to produce the diastereo-isomer (E); (e) reacting 2-hydroxy-methyl cyclopentanone with the benzyl ester of glycine; (f) hydrogenating the prod. to give endocis-2-arabicyclo (3,3,O) octano 3-carboxylic acid; (g) reacting this with (S)-1-(1-naphthyl) ethylamine to give (1S,3S,5S)-2-arabicyclo (3,3,O)-octano 3-carboxylic acid; (h) conversion to the acid chloride; (i) esterification with benzyl alcohol to the benzyl ester (K); (j) combining (E) and (K) and dehydration with dicyclohexyl carbo-diamide to give the benzyl ester of 2N-(S)-1-ethoxycarboxyl 3-phenyl propyl L-alanyl (1S,3S,5S)-arabicyclo (3,3,O)-octano 3-carboxylic acid; and (k) debenzylating by hydrogenolysis to obtain the free acid. - (E) is (S,S)-2N-(1-ethoxy carbonyl) 3-phenyl-propyl alanine.
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