2,5-anhydro-1-[[1-(trimethylacetoxy)ethoxy]carbonyl]amino-1,4-dideoxy-3-thio-D-threo-pentitol

(4R,5S,6S)-3-((2R,3R)-2-{[1-(2,2-dimethyl-propionyloxy)ethoxycarbonylamino]-methyl}-tetrahydrofuran-3-yl-sulfanyl)-6-(1R-hydroxyethyl)-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrophenylmethyl ester