(R)-6-[(1E,3Z,7E,9E)-(5R,14R)-14-(tert-Butyl-dimethyl-silanyloxy)-3-ethyl-5,9-dimethyl-12-(tetrahydro-pyran-2-yloxy)-heptadeca-1,3,7,9-tetraenyl]-5,6-dihydro-pyran-2-one