((E)-(1R,2S)-6-Benzyloxy-1-{(R)-1-[(4S,5S)-5-(4-methoxy-benzyloxymethyl)-2,2-dimethyl-[1,3]dioxan-4-yl]-ethyl}-2,4-dimethyl-hex-4-enyloxy)-tert-butyl-dimethyl-silane