$k=1$, các đồng phân cấu tạo đơn chức, tạp chức là:
(1) $HCOOCH_2-CH_2-CH_3$
(2) $HCOO-CH(CH_3)_2$
(3) $CH_3COOC_2H_5$
(4) $C_2H_5COOCH_3$
(5) $CH_3-CH_2-CH_2-COOH$
(6) $CH_3-CH(CH_3)-COOH$
(7) $HO-CH_2-CH_2-CH_2-CHO$
(8) $CH_3-CH(OH)-CH_2-CHO$
(9) $CH_3-CH_2-CH(OH)-CHO$
(10) $CH_2OH-CH(CH_3)-CHO$
(11) $(CH_3)_2C(OH)-CHO$
(12) $CH_3-O-CH_2-CH_2-CHO$
(13) $CH_3-O-CH(CH_3)-CHO$
(14) $C_2H_5-O-CH_2-CHO$
(15) $CH_2OH-CH_2-CO-CH_3$
(16) $CH_3-CH(OH)-CO-CH_3$
(17) $CH_3-CH_2-CO-CH_2OH$
(18) $CH_3-O-CH_2-CO-CH_3$
(19) $CH_2OH-CHOH-CH=CH_2$
(20) $CH_2OH-CH=CH-CH_2OH$
(21) $CH_2OH-O-CH_2-CH=CH_2$
(22) $CH_3-O-CHOH-CH=CH_2$
(23) $CH_2OH-CH_2-O-CH=CH_2$
(24) $CH_3-CHOH-O-CH=CH_2$
(25) $CH_2OH-CH=CH-O-CH_3$
(26) $CH_3-CH=CH-O-CH_2OH$
(27) $CH_3-O-O-CH_2-CH=CH_2$
(28) $CH_3-O-CH_2-O-CH=CH_2$
(29) $CH_3-CH_2-O-O-CH=CH_2$
(30) $CH_3-O-O-CH=CH-CH_3$
(31) $CH_3-O-CH=CH-O-CH_3$
(32) $CH_2OH-C(=CH_2)-CH_2OH$
(33) $CH_2OH-C(=CH_2)-O-CH_3$
(34) $CH_3-O-C(=CH_2)-O-CH_3$
(35) $CH_3-O-O-C(=CH_2)-CH_3$
Đồng phân mạch vòng như hình
Trước mắt là có $42$ đồng phân.
