摘要:
(S,S)-alpha,alpha'-Diamino-1,4- and 1,3-benzenediacetic acids and N-Boc- and N-Fmoc-derivatives have been prepared by stereoselective syntheses. The chiral auxiliary (S)-4-benzyl-2-oxazolidinone formed bisimides with benzenediacetyl dichlorides The imides were lithiated at both a-sites to the carbonyl groups and azidated stereoselectively alpha to both carbonyl groups by trisyl azide to provide (S,S)-alpha,alpha'-diazidobenzenediacetic acid derivatives which were reduced to amines by Sn(II) chloride or by hydrogenolysis over Pd. Copyright (C) 1996 Elsevier Science Ltd