2,6-Tridecadienal,13-(2,5-dimethoxy-3-nitrophenyl)-5-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-4,9,10,13-tetramethoxy-6,8,12-trimethyl-,(2Z,4S,5S,6E,8S,9R,10S,12S,13R)-