1-(4-Ethynylphenyl)-4-methyl-2,6,7-trioxabicyclo(2.2.2)octane 134133-78-1 2,6,7-Trioxabicyclo(2.2.2)octane, 1-(4-ethynylphenyl)-4-methyl- 4-Methyl-1-(4-ethynylphenyl)-2,6,7-trioxabicyclo(2.2.2)octane