5-Isopropenyl-1-{(4R,5S)-5-[(Z)-(S)-3-(4-methoxy-benzyloxymethyl)-1-methoxymethoxy-penta-2,4-dienyl]-2,2-dimethyl-[1,3]dioxolan-4-yl}-6-methyl-2-methylene-hept-5-en-1-one