1-(4-Ethynylphenyl)-4-(1-methyl-2-propenyl)-2,6,7-trioxabicyclo(2.2.2)octane 134133-85-0 2,6,7-Trioxabicyclo(2.2.2)octane, 1-(4-ethynylphenyl)-4-(1-methyl-2-propenyl)-