Absolute structure determination of (2R,10S)-2-(10-benzyl- 20-hydroxyethylamino)-4-phenylbutanoic acid

Crystallization-induced asymmetric transformation was employed to prepare a labile g-oxo-a-aminoacid (3) with a new stereogenic center in high diastereomeric and enantiomeric purity. Compound 3 was reduced to a stable compound, (2R,10S)-2-(10-benzyl-20-hydrohydroxyethylamino)- 4-phenylbutanoic acid (4), which crystallizes in space group P21. Upon deprotonation, 4 becomes a tridentate monoanionic chelating ligand, 42H, which reacts with copper nitrate yielding [Cu(42H)(H2O)2]NO3·H2O (5). Complex 5 crystallizes in space group P21 and has a rare composition among crystallographically characterized mononuclear five-coordinate transition metal complexes. The absolute structure determination of 5 allowed by inference the assignment of absolute configuration to compound 3. q 2004 Elsevier B.V. All rights reserved