2,4,8-Pentadecatrienoic acid,15-(2,5-dimethoxy-3-nitrophenyl)-7-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-6,11,12,15-tetramethoxy-2,8,10,14-tetramethyl-, methyl ester,(2E,4Z,6S,7S,8E,10S,11R,12S,14S,15R)-