(3S,4R)-3-[(R)-1-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-1-methylsulfanyl-4-((R)-1-trimethylsilanyloxymethyl-allyl)-azetidin-2-one

Methanesulfonic acid (R)-2-{(2R,3S)-3-[(R)-1-(tert-butyl-dimethyl-silanyloxy)-ethyl]-4-oxo-azetidin-2-yl}-but-3-enyl ester