H3C—CH(CH3)—CH2—CH2—CH3
H3C—CH(CH3)—CH2—CH(CH3)—CH2—CH3
H3C—C(CH3)2—CH(C2H5)—CH(CH3)—CH2—CH2—CH3
.............................
H3C—CH(CH3)—CH2—CH2—CH3
H3C—CH(CH3)—CH2—CH(CH3)—CH2—CH3
H3C—C(CH3)2—CH(C2H5)—CH(CH3)—CH2—CH2—CH3
.............................