(2S,4R)-4-ethoxy-1-{[(9H-fluoren-9-yl)methoxy]carbonyl}pyrrolidine-2-carboxylic acid

(2S,4R)-4-ethoxy-N-methylpyrrolidine-2-carboxamide hydrochloride

(2S,4R)-4-ethoxypyrrolidine-2-carboxylic acid hydrochloride

(2S,4R)-4-fluoro-1-methyl-5-oxopyrrolidine-2-carboxylic acid

(2S,4R)-4-fluoro-1-methylpyrrolidine-2-carboxylic acid hydrochloride

(2S,4R)-4-fluoro-2-(trifluoromethyl)pyrrolidine hydrochloride

(2S,4R)-4-fluoro-5-oxopyrrolidine-2-carboxylic acid

(2S,4R)-4-fluoro-N-methylpyrrolidine-2-carboxamide hydrochloride

(2S,4R)-4-fluoro-N-[(S)-phenyl[4-(propan-2-yl)phenyl]methyl]-1-[2-(1H-1,2,3-triazol-5-yl)acetyl]pyrrolidine-2-carboxamide

(2S,4R)-4-fluoropyrrolidine-2-carbonitrile; 4-methylbenzene-1-sulfonic acid

(2S,4R)-4-fluoropyrrolidine-2-carboxamide

(2S,4R)-4-fluoropyrrolidine-2-carboxylic acid hydrochloride

(2S,4R)-4-hydroxy-1-(1-methyl-1H-1,2,3,4-tetrazol-5-yl)pyrrolidine-2-carboxylic acid

(2S,4R)-4-hydroxy-1-(4-methylbenzenesulfonyl)pyrrolidine-2-carboxylic acid

(2S,4R)-4-hydroxy-1-methylpyrrolidine-2-carboxylic acid

(2S,4R)-4-hydroxy-2-methyl-2H,3H,4H-1lambda6-thieno[2,3-b]thiopyran-1,1-dione

(2S,4R)-4-hydroxy-N,N-dimethylpyrrolidine-2-carboxamide hydrochloride

(2S,4R)-4-hydroxy-N-methylpyrrolidine-2-carboxamide hydrochloride

(2S,4R)-4-hydroxy-N-{[2-hydroxy-4-(4-methyl-1,3-thiazol-5-yl)phenyl]methyl}-1-[(2S)-3-methyl-2-(1-oxo-2,3-dihydro-1H-isoindol-2-yl)butanoyl]pyrrolidine-2-carboxamide

(2S,4R)-4-hydroxy-N-{[2-hydroxy-4-(4-methyl-1,3-thiazol-5-yl)phenyl]methyl}pyrrolidine-2-carboxamide dihydrochloride

(2S,4R)-4-hydroxy-N-{[4-(4-methyl-1,3-thiazol-5-yl)-3-(trifluoromethyl)phenyl]methyl}pyrrolidine-2-carboxamide dihydrochloride

(2S,4R)-4-hydroxy-N-{[4-(4-methyl-1,3-thiazol-5-yl)phenyl]methyl}pyrrolidine-2-carboxamide dihydrochloride

(2S,4R)-4-hydroxypiperidine-2-carboxylic acid hydrochloride

(2S,4R)-4-hydroxypyrrolidine-2-carbohydrazide hydrochloride

(2S,4R)-4-hydroxypyrrolidine-2-carboxamide

(2S,4R)-4-hydroxypyrrolidine-2-carboxamide hydrochloride

(2S,4R)-4-hydroxypyrrolidine-2-carboxylic acid

(2S,4R)-4-methanesulfonylpyrrolidine-2-carboxylic acid hydrochloride

(2S,4R)-4-methoxy-2-(methoxymethyl)pyrrolidine hydrochloride

(2S,4R)-4-methoxy-2-{5H,6H,7H-pyrrolo[2,1-c][1,2,4]triazol-3-yl}pyrrolidine

(2S,4R)-4-methoxy-2-{[1,2,4]triazolo[4,3-a]pyrazin-3-yl}pyrrolidine

(2S,4R)-4-methoxypyrrolidine-2-carboxylic acid

(2S,4R)-4-methoxypyrrolidine-2-carboxylic acid hydrochloride

(2S,4R)-4-methylpyrrolidine-2-carboxylic acid

(2S,4R)-4-sulfanylpyrrolidine-2-carboxylic acid

(2S,4R)-4-[(tert-butyldimethylsilyl)oxy]pyrrolidine-2-carboxylic acid

(2S,4R)-4-{[(benzyloxy)carbonyl]amino}-1-[(tert-butoxy)carbonyl]pyrrolidine-2-carboxylic acid

(2S,4R)-4-{[(tert-butoxy)carbonyl]amino}-1-{[(9H-fluoren-9-yl)methoxy]carbonyl}pyrrolidine-2-carboxylic acid

(2s,4r)-5-azaspiro[3.5]nonan-2-ol hydrochloride

(2s,4r)-5-azaspiro[3.5]nonane-2-carboxylic acid hydrochloride

(2S,4R)-5-azido-2-{[(tert-butoxy)carbonyl]amino}-4-fluoropentanoic acid

(2s,4r)-5-[(tert-butoxy)carbonyl]-5-azaspiro[3.5]nonane-2-carboxylic acid

(2s,4r)-6-aminospiro[3.5]nonane-2-carboxylic acid hydrochloride

(2s,4r)-6-azaspiro[3.5]nonan-2-ol hydrochloride

(2S,4R)-N-({2-[2-(2-{2-[(6-chlorohexyl)oxy]ethoxy}ethoxy)ethoxy]-4-(4-methyl-1,3-thiazol-5-yl)phenyl}methyl)-1-[(2S)-2-[(1-cyanocyclopropyl)formamido]-3,3-dimethylbutanoyl]-4-hydroxypyrrolidine-2-carboxamide