(4R,5R)-methyl 5-{(1E,3R,7S,9E,11R,12S,13R,14R)-12-[(tert-butyldimethylsilyl)oxy]-8-hydroxy-14-methoxy-16-[(4-methoxybenzyl)oxy]-3,7,9,11,13-pentamethylhexadeca-1,9-dienyl}-2,2-dimethyl-1,3-dioxalone-4-carboxylate