2-methyl-but-2-enoic acid 3-(tert-butyl-dimethyl-silanyloxy)-5-[3-(dimethyl-phenyl-silanyl)-3-phenyl-acryloyloxy]-6-hydroxymethyl-2-[2,2,4-trimethyl-6-(1-propyl-but-3-enyloxy)-tetrahydro-[1,3]dioxolo[4,5-c]pyran-7-yloxy]-tetrahydro-pyran-4-yl ester