2 3-dimethylhept-3-ene July 8, 2019 16 32 64 128 2 3 dimethylhept 3 ene 2 3-dimethylhept-2-ene 2 3-dimethyl-4-ethylheptane 2 3-dimethyl heptane 2 3-dimethyl-3-ethylhexane 2 3-dimethylheptane structural formula