(2S,4S)-4-Mercapto-2-(1-phenyl-1H-tetrazol-5-ylsulfanylmethyl)-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-4-Mercapto-2-(1-pyridin-4-yl-1H-tetrazol-5-ylsulfanylmethyl)-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-4-Mercapto-2-[1-(2-methylcarbamoyl-ethyl)-1H-tetrazol-5-ylsulfanylmethyl]-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-2-[1-(2-Dimethylsulfamoyl-ethyl)-1H-tetrazol-5-ylsulfanylmethyl]-4-mercapto-pyrrolidine-1-carboxylic acid allyl ester

(4R,5S,6S)-3-{(3S,5S)-1-Allyloxycarbonyl-5-[1-(2-carbamoyl-ethyl)-1H-tetrazol-5-ylsulfanylmethyl]-pyrrolidin-3-ylsulfanyl}-6-((R)-1-hydroxy-ethyl)-4-methyl-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid allyl ester