We have 2,2- dimethylpropane (an isomer of pentane) but can't we have 2- ethylpropane. Share with your friends Share 0 Akanksha Jain answered this 2-Ethylpropane doesn't exist as in that case, parent chain is of 4 carbons and not 2 carbons. So its correct name will be 2-Methylbutane. CH3-C/H-CH3 CH2-CH3 1 View Full Answer Mariah Banu answered this No we can't have 2 - ethylpropane as there aren't enough atoms in ethylproane to form 2 - eithylpropane 0