[摘要]：Chiral ortho esters of a-isocyano acids were synthesized from com. available Cbz-protected a-amino acids. These compds. are stable toward racemization in the Ugi 4CC in contrast to known esters of a-isocyano acids. Applying them in Ugi 4CC with subsequent deprotection gives access to dipeptides with preserved configuration at the C-terminal amino acid. |
