(2S,3S)-trans-Epoxysuccinyl-L-leucylamido-3-methylbutane 76684-89-4 NSC694279 Oxiranecarboxylic acid, 3-[[(3-methyl-1-[[(3-methylbutyl) amino]carbonyl]butyl]amino]carbonyl]-, [2S-[2.alpha.,3.beta.(R*)]]-