(3S,3R)-2,5-diethoxy-3,6-dihydro-3-isopropyl-6-methylpyrazine

3-methyl-6-propan-2-ylpiperazine-2,5-dione

(S)-2-Amino-1-((1S,5R,7R)-10,10-dimethyl-3,3-dioxo-3λ6-thia-4-aza-tricyclo[5.2.1.01,5]dec-4-yl)-3-methyl-butan-1-one; hydrochloride

(2S,5S)-1-benzyloxycarbonyl-2-t-butyl-3-methyl-5-(prop-2-yl)-4-imidazolidinone

D-5-isopropylhydantoin