Synthesis of the spin-labelled beta-amino acids cis- and trans-beta-TOAC, and conformational study of a trans-beta-TOAC/ACHC hexapeptide

摘要

The spin-labelled, cyclic, chiral beta-amino acids cis-beta-TOAC and trans-beta-TOAC, have been synthesised in an enantiomerically pure form by amination of 3-carboxymethyl-1-oxyl-2,2,6,6-tetramethyl-4-piperidone with (R)- or (S)-alfa-methyl-benzylamine, followed by reduction with NaBH3CN/CH3COOH or NaBH4/(CH3)2CHCOOH. The 3D-structure of the hexapeptide 1, prepared by 4+2 segment coupling in solution, has been preliminarily analyzed by spectroscopic techniques.