Ramipril diketopiperazine; Ramipril USP Related Compound D; (S)-ethyl 2-((3S,5aS,8aS,9aS)-3-methyl-1,4-dioxooctahydro-1H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-2(5aH)-yl)-4-phenylbutanoate;(alphaS,3S,5aalpha,8aalpha,9aalpha)-alpha-Phenethyl-1,4-dioxo-3beta-methyldecahydro-2H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazine-2-acetic acid ethyl ester;(S)-Ethyl 2-((3S,5aS,8aS,9aS)-3-methyl-1,4-dioxooctahydro-1H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-2(5aH)-yl)-4-phenylbutanoate;ethyl (2S)-2-[(2S,4aS,5aS,8aS)-2-methyl-1,4-dioxo-2,4a,5,5a,6,7,8,8a-octahydrocyclopenta[3,4]pyrrolo[3,5-c]pyrazin-3-yl]-4-phenylbutanoate;Ethyl (2S)-2-[(3S,5aS,8aS,9aS)-3-Methyl-1,4-dioxodecahydro-2H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-2-yl]-4-phenylbutanoate (Ramipril Diketopiperazine)
