methyl 2-((2R,3S)-3-((S)-1-((tert-butyldimethylsilyl)oxy)ethyl)-2-(methylthio)-4-oxoazetidin-1-yl)-3-methylbut-2-enoate

(5R)-6ξ-((R)-1-hydroxy-ethyl)-3,3-dimethyl-7-oxo-(5rH)-4-thia-1-aza-bicyclo[3.2.0]heptane-2c-carboxylic acid benzyl ester

4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-(1-hydroxyethyl)-3,3-dimethyl-7-oxo-6-(phenylseleno)-, phenylmethylester, [2S-[2a,5a,6b,6(S*)]]-