tert-Butyl-[(4Z,9Z)-(1R,6S,7S,8S)-7-(4-methoxy-benzyloxy)-1-[(Z)-(1R,2S,3S)-2-(4-methoxy-benzyloxy)-1,3-dimethyl-hepta-4,6-dienyl]-6,8-dimethyl-13-(tetrahydro-pyran-2-yloxy)-trideca-4,9-dienyloxy]-dimethyl-silane