4-Benzyloxy-3,5-dichloro-2-methoxy-6-methyl-benzoic acid (2R,3R,4R,6S)-6-[(2R,3R,4S,5R)-4-benzyloxy-5,6-bis-(4-methoxy-benzyloxy)-2-methyl-tetrahydro-pyran-3-yloxy]-2-methyl-4-triisopropylsilanyloxy-tetrahydro-pyran-3-yl ester