(2S,3S,4R,5S,6R)-3,4-Diacetoxy-6-((2R,3S,4R,5R)-6-acetoxy-2-acetoxymethyl-5-azido-4-benzyloxy-tetrahydro-pyran-3-yloxy)-5-azido-tetrahydro-pyran-2-carboxylic acid benzyl ester