(1S)-1-{(1R,2R,3R)-2-{[tert-butyl(dimethyl)silyl]oxy}-5-[(3,4-dimethoxybenzyl)oxy]-1,3-dimethylpentyl}pent-3-ynyl 2,4-dimethoxy-6-{(2R,3S)-3-methyl-2-[(triisopropylsilyl)oxy]hept-5-ynyl}benzoate