4-Amino-1-oxyl-2,2,6,6,-tetramethylpiperidine-3-carboxylic acid (beta-TOAC), the first spin-labelled, cyclic, chiral beta-amino acid resolved in an enantiomerically pure state

摘要

Amination of 3-carboxymethyl-1-oxyl-2,2,6,6-tetramethyl-4-piperidone with (R)-alpha-methylbenzylamine. NaBH_3CN reduction of the resulting enamine and removal of the chiral auxiliary from the separated diastereoisomers, led to enantiomerically pure (3S, 4S) and (3R,4R) methyl 4-amino-1-oxyl-2,2,6,6-tetramethylpiperidine-2-carboxylates.