丁烷:分子式C4H10,同分异构体2种,CH3CH2CH2CH3,CH3CH(CH3)2,
戊烷:分子式C5H10,同分异构体3种,CH3CH2CH2CH2CH3,CH3CH(CH3)CH2CH3,C(CH3)4
己烷:分子式C6H14,同分异构体5种,CH3CH2CH2CH2CH2CH3,CH3CH(CH3)CH2CH2CH3,CH3CH2CH(CH3)CH2CH3,CH3C(CH3)2CH2CH3,(CH3)2CHCH(CH3)2
庚烷:分子式C7H16,同分异构体9种,CH3CH2CH2CH2CH2CH2CH3,CH3CH(CH3)CH2CH2CH2CH3,CH3CH2CH(CH3)CH2CH2CH3,CH3C(CH3)2CH2CH2CH3,CH3CH2C(CH3)2CH2CH3,CH3CH(CH3)CH(CH3)CH2CH3,CH3CH(CH3)CH2CH(CH3)CH3,CH3CH2CH(CH2CH3)2,CH3C(CH3)2CH(CH3)2