The readily available 2,4,6-tri(terf-buty1)-and 2,6-di(tert-butyl)-4-methoxyphenol esters 2 of a-nitrocyclopropanecarboxylic acid undergo ring opening with C-, N-, 0-, and S-nucleophiles (cyanide, malonate, azide, anilines, alkoxides, phenoxides, thiolates) in DMF or alcohol solvents (80-95 % yield). The products C 1 4 are 2-nitrobutanoates with the newly introduced substituent in the 4-position. Reduction of the NO, group with Zn/AcOH/Ac20 gives N-acetyl-a-amino acid esters 1 6 2 2 (40-90 % yield). Subsequent oxidative cleavage (H202/ HCOOH) of thep-methoxy-phenyl esters 18 and 20 produces free amino acids (65% 23 and 67% 24, respectively). Thus, the nitro ester 2 corresponds to a 2-aminobutanoic-acid a4-synthon, it is a 'homo-Michael acceptor' producing y-substituted a-amino acids.