tri-tert-butyl [1S,1(3R,4S,5R),3S,4S,5R,6R,7R]-7-(tert-butoxycarbonyl)oxy-4,6-dihydroxy-1-[4-hydroxy-3-(hydroxymethyl)-5-methyl-6-phenylhexyl]-2,8-dioxabicyclo[3.2.1]octane-3,4,5-tricarboxylate