(4R,5S,6S)-6-((R)-1-Hydroxy-ethyl)-3-[(2R,3R,4R)-2-methoxycarbonyl-4-(toluene-4-sulfonyloxymethyl)-oxetan-3-ylsulfanyl]-4-methyl-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester

methyl 2,4-anhydro-5-O-tertbutyldiphenylsilyl-D-arabinonate

(2R,3R,4R)-4-(tert-Butyl-diphenyl-silanyloxymethyl)-3-(4-methoxy-benzylsulfanyl)-oxetane-2-carboxylic acid dimethylamide