Side Chain For Imipenem

(R)-2-[(3S,4S)-3-[(R)-1-(tert-; -methylazetidin-2-one; (2R)-2-[(2S)-3ß-[(R)-1-(tert-Butyldimethylsiloxy)ethyl]-4-oxoazetidine-2a-yl]propanoic acid; (2R)-2-[(2S,3S)-3-[(1R)-1-(tert-Butyldimethylsilyloxy)ethyl]-4-oxoazetidine-2-yl]propanoic acid; (2R)-2-[(3S)-2-Oxo-3a-[(1R)-1-(tert-butyldimethylsiloxy)ethyl]azetidine-4ß-yl]propionic acid; (R)-2-[(2S)-3ß-[(R)-1-(tert-Butyldimethylsilyloxy)ethyl]-4-oxoazetidine-2a-yl]propanoic acid; (R)-2-[(2S,3S)-3ß-[(R)-1-(tert-Butyldimethylsiloxy)ethyl]-4-oxoazetidin-2a-yl]propionic acid; (aR,2S)-a-Methyl-3ß-[(R)-1-(tert-butyldimethylsiloxy)ethyl]-4-oxoazetidine-2a-acetic acid