4-Undecenamide,11-(2,5-dimethoxy-3-nitrophenyl)-3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-8-hydroxy-N,7,11-trimethoxy-N,2,4,6,10-pentamethyl-9-[(2-thioxo-3-thiazolidinyl)carbonyl]-