(2R,3S,4R,5R,7R)-1-[(4R,5S)-5-(2-Benzyloxy-ethyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-7-(tert-butyl-dimethyl-silanyloxy)-3-hydroxy-8-methoxy-5-(4-methoxy-benzyloxy)-2,4-dimethyl-octan-1-one