6-Oxabicyclo[3.2.1]octan-8-one,4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1-[(1R,3E)-1-hydroxy-4-methyl-3,5-hexadienyl]-5-methyl-2-(1-methylethenyl)-, (1R,2R,4S,5R)-