4 ethyl 3 3 dimethylheptane July 8, 2019 16 32 64 128 4 ethyl 3 3 dimethylheptane structural formula 4 ethyl 3 3 dimethylheptane structure 4 4-dimethyl 3-ethyl heptane 4 bromo 5 ethyl 3 3 dimethylheptane