Question 13.3:-

For the following compounds, write structural formulas and IUPAC names for all possible isomers having the number of a double or triple bond as indicated :

(a) C4H8 (one double bond)

(b) C5H8 (one triple bond) 


 (a) The following structural isomers are possible for C4H8 with one double bond:

 H2C1=CH2-CH32-CH43                (I)CH13-CH2=CH3-CH43               (II)CH21=C2-CH33             |          CH3          (III)

 The IUPAC name of

 Compound (I) is But-1-ene,

 Compound (II) is But-2-ene, and

 Compound (III) is 2-Methylprop-1-ene.

 (b) The following structural isomers are possible for C5H8 with one triple bond: 

 HC1=C2-C3H2-C4H2-C5H3                 (I) H2C1-C2=C3-C4H-C5H3             (II)H2 C4-C3H-C2=C1H             |              CH3              (III)

 The IUPAC name of

Compound (I) is Pent-1-yne, Compound

(II) is Pent-2-yne, and

Compound (III) is 3-Methylbut-1-ene