1) CH3 - CH(CH3) - CH2 - C(CH2-CH3)(CH2-CH3) - CH2 - CH2 - CH2 - CH3
2) CH3 - CH2 - C(CH2-CH3)(CH3) - CH2 - CH2 - CH3
3) CH3 - CH(CH3) - CH(CH3) - CH2 - CH2 - CH2 - CH3
4) CH3 - CH2 - CH(CH2-CH3) - CH2 - CH2 - CH3
5) CH3 - CH2 - CH(CH2-CH2-CH3) - CH2 - CH(CH3) - CH2 - CH3
6) CH3 - CH(CH3) - CH2 - CH(CH3) - CH2 - CH3