((1aR,1a1R,3aR,5R,5aR)-1a-(((2S,3R,4S,5R,6R)-3-acetoxy-4,5-bis(benzyloxy)-6-((benzyloxy)methyl)tetrahydro-2H-pyran-2-yl)oxy)-5-((tert-butyldimethylsilyl)oxy)-2-oxohexahydro-3-oxacyclobuta[cd]pentalen-1a1(1H)-yl)methyl benzoate