(2S,3R,8S,9R,10S,11Z,13S,15S,16R,17E)-9,13,15-tris(tert-butyldimethylsilyloxy)-2-((4S,5S)-2-(4-methoxyphenyl)-5-methyl-1,3-dioxan-4-yl)-8,10,16-trimethyl-19-(trityloxy)nonadeca-11,17-dien-3-ol