Chapter 21.3, Problem 22SSC

Interpretation Introduction

Interpretation:

The molecular structure of 4-methyl-1, 3-pentadiene and 2, 3-dimethyl-2-butene needs to be drawn.

Concept introduction:

The hydrocarbon compounds that is compound containing only hydrogen and carbon atoms that contains multiple bond(s) are said to be unsaturated hydrocarbon. Compounds containing double bonds are said to be alkene whereas compounds containing triple bonds are said to be alkyne.

Answer to Problem 22SSC

The structure of:

• 4-methyl-1, 3-pentadiene is:

• 2, 3-dimethyl-2-butene is:

Explanation of Solution

Alkenes are compounds containing carbon and hydrogen atoms with one more double bond(s) between carbon atom(s) in the structure. For number of carbons atoms in alkene chain, the prefix is given as:

Carbon-1   meth

Carbon-2   eth

Carbon-3   prop    

Carbon-4   but      

Carbon-5   pent

Carbon-6   hex

Carbon-7   hept

Carbon-8   oct

Carbon-9   non     

Carbon-10       dec

The numbering of the carbon chain is done in such a way that the multiple bond(s) and substituents gets the lower number.

The given name is 4-methyl-1, 3-pentadiene that means the parent chain has 5 number of carbons in the chain and -diene represents the presence of two double bonds in the molecule at position 1 and 3 and 4-methyl represents presence of methyl substituent at carbon-4. So, the structure of 4-methyl-1, 3-pentadiene is:

The given name is 2, 3-dimethyl-2-butenethat means the parent chain has 4 number of carbons in the chain and -diene represents the presence of two double bonds in the molecule at position 2 and 3. So, the structure of 2, 3-dimethyl-2-butene is: