(Z)-(R)-8-{(4S,6R)-6-[1-Acetoxy-2-nitro-3-(2-pentyl-[1,3]dioxolan-2-yl)-propyl]-2,2-dimethyl-[1,3]dioxan-4-yl}-8-(tert-butyl-diphenyl-silanyloxy)-oct-5-enoic acid methyl ester