(R)-6-((1E,3Z,5R,7E,9E,11R,12R,13S,14R,15S)-14-(tert-butyl(dimethyl)silyloxy)-3-ethyl-5,9,11,13,15-pentamethyl-12-oxo-heptadeca-1,3,7,9-tetraenyl)-5,6-dihydro-2H-pyran-2-one