1-[6-[[4-(tert-butyl-dimethyl-silanyloxy)-6-(4-chloro-butyl)-2-methoxy-5-methyl-tetrahydro-pyran-2-yl]-(4-methoxy-benzyloxy)-methyl]-3,4-bis-(4-methoxy-benzyloxy)-5-methyl-tetrahydro-pyran-2-yl]-7-chloro-4-hydroxy-octa-5,7-dien-2-one