methyl <2E,4E,6R*(1S*-<1α,3α,4β,5α,6α,8β>)>-6-(6-((tert-butyldimethylsilyl)oxy)-1,4,8-trimethyl-2,9-dioxabicyclo<3.3.1>nonan-3-yl)-4-methylhepta-2,4-dienoate