Synthesis of New 2,2,5,5-Tetramethyl-2,5-dihydro-1H-pyrrol-1-yloxyl Radicals and 2-Substituted-2,5,5-trimethylpyrrolidin-1-yloxyl Radicals Based α-Amino Acids - Balog, Mária; Kálai, Tamás; Jekő, József; Steinhoff, Heinz-Jürgen; Engelhard, Martin; Hideg, Kálmán (Synlett, 2004)