(1R,3R,4R,5R,6R,7R)-3-ethyl-7-<(1E,3E)-4-formylbuta-1,3-dienyl>-4,6-dihydroxy-4,5-dimethyl-2,8-dioxabicyclo<3.3.0>octane

(1R,3R,4R,5R,6R,7R)-7-<(1E,3E)-4-(ethoxycarbonyl)buta-1,3-dienyl>-3-ethyl-4,6-dihydroxy-4,5-dimethyl-2,8-dioxabicyclo<3.3.0>octane