Acetic acid (2R,3R,4S,5R,6R)-3,4,5-tris-benzyloxy-6-[(1S,13R)-1-((R)-6-benzyloxy-heptyl)-15-(tert-butyl-diphenyl-silanyloxy)-13-(4-methoxy-benzyloxy)-pentadecyloxy]-tetrahydro-pyran-2-ylmethyl ester