(E)-(2S,10R)-2-Benzyloxy-1-{(4R,6S)-6-[2-(tert-butyl-diphenyl-silanyloxy)-ethyl]-2,2-dimethyl-[1,3]dioxan-4-yl}-3,3-dimethyl-10-triethylsilanyloxy-dodeca-5,11-dien-4-one