Question

4. Draw structures corresponding to the following systematic names; a) 1-isopropyl-4-methylcyclohexene b) 3-butyl-2-heptene c) 4-methyl-1,2- hexadiene d) trans-3,3-dimethyl-4-propyl-1,5-octadiene e) (42)-2,4-diethyl-1,4-hexadiene f) 1.2-propadiene g) (32,5E) -2,6-dimethyl-1,3,5,7-octatetraene h) cis-2,2,5,5-tetramethyl-3-hexene i) Methylenecyclohexane, j) trans- 1,2 divinylcyclohexane

Answer 1

a) 1-isopropyl-4-methylcyclohexene

I-0-0 0- H-C-H I-U

Explanation

1-isopropyl-4-methylcyclohexene

Last part of the name is the parent name , here it is cyclohexene : it implies that hex means 6 carbon atoms ,and

cyclo means (6 carbon atoms) connected forming a ring

And ene means there is a double bond , but no number is given , which means double bond is at 1st carbon atom (therefore between 1st and 2nd carbon atoms )

Now you have to number them as 1 , 2 , 3 , 4 ,5 , 6

Now , see the substituents

4-methyl is a methyl (-CH₃) substituent at 4th carbon atom

1-isopropyl means isopropyl group at 1st carbon

This explaination on the structure is as follows

H H Isopropyl I - H group I HC5H I TH-C-H tu- I Methyl group

(b) 3-butyl-2-heptene

и 2-С-ін бун н, инні ни . С н н н н н н н н

Explanation

3-butyl-2-heptene

Last part of the name is the parent name , here it is

2-heptene : is parent chain

hept means 7 Carbon atoms in a chain

ene in 2-heptene means there is a double bond at 2nd carbon ( therefore between 2nd and 3rd carbon).

Now you have to number them as 1 , 2 , 3 , 4 ,5 , 6 ,7

Now , see the substituents

3-butyl means butyl group at 3rd carbon atom

This explaination on the structure is as follows

H ин H н Ś 16/7H H H H H H H H H Butyl group at 3rd carbon atom

(c) 4-methyl-1,2-hexadiene

cm H

Explanation

4-methyl-1,2-hexadiene

Last part of the name is the parent name , here it is

1,2-hexadiene is the parent chain

hex means 6 carbon atoms in a chain

1,2-hexadiene means there are 2 double bond : one at 1st carbon atom( therefore between 1st and 2nd carbon). and second at 2nd carbon atom( therefore between 2nd and 3rd carbon).

Now the substituent is methyl at 4th carbon ,

Explained in image as follows

Methyl group at 4th carbon

(d) trans-3,3-dimethyl-4-propyl-1,5-octadiene

H H H 1- C-Var HY { Ch it HAIR H

Explanation

1,5-octadiene means it has 8 carbon atom chain and there are two double bonds at first and fifth carbon atom

There is a propyl substituent at fourth position

And 2 methyl substituents at third carbon atom

The double bond at fifth carbon atom has a trans configuration

2 / с с I-nu син н/ Two methyl groups at 3rd Carbon