English
Karnataka Board PUCPUC Science Class 11

An alkene ‘A’ on ozonolysis gives a mixture of ethanal and pentan-3-one. Write structure and IUPAC name of ‘A’.

Advertisements
Advertisements

Question

An alkene ‘A’ on ozonolysis gives a mixture of ethanal and pentan-3-one. Write structure and IUPAC name of ‘A’.

Answer in Brief
Advertisements

Solution

\[\begin{array}{cc}
\phantom{....................................................}\ce{^5CH3}\\
\phantom{..................................................}|\\
\phantom{...................................................}\ce{^4CH2}\\
\phantom{..................................................}|\\
\ce{A + O3 ->[Zn + H2O] H3C - C = O + ^1CH3 - ^2CH2 - ^3C}\\
\phantom{.......................}|\phantom{...........................}||\\
\phantom{.........................}\ce{\underset{Ethanal}{H}}\phantom{....................}\ce{\underset{Pentan - 3 - one}{O}}
\end{array}\]

During ozonolysis, an ozonide having a cyclic structure is formed as an intermediate which undergoes cleavage to give the final products. Ethanal and pentan-3-one are obtained from the intermediate ozonide. Hence, the expected structure of the ozonide is:

This ozonide is formed as an addition of ozone to ‘A’. The desired structure of ‘A’ can be obtained by the removal of ozone from the ozonide. Hence, the structural formula of ‘A’ is:

\[\begin{array}{cc}
\ce{H3^1C - ^2CH = ^3C - ^4CH2 - ^5CH3}\\
\phantom{.}|\\\phantom{..........}\ce{CH2 - CH3}\end{array}\]

The IUPAC name of ‘A’ is 3-Ethylpent-2-ene.

shaalaa.com
  Is there an error in this question or solution?
Chapter 9: Hydrocarbons - EXERCISES [Page 405]

APPEARS IN

NCERT Chemistry Part 1 and 2 [English] Class 11
Chapter 9 Hydrocarbons
EXERCISES | Q 13.5 | Page 405

RELATED QUESTIONS

Write IUPAC name of the product obtained by the ozonolysis of the following compound.

Pent-2-ene


An alkene ‘A’ contains three C – C, eight C – H σ bonds and one C – C π bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’.


Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?


Write a chemical equation for combustion reaction of the following hydrocarbon:

Butane


Write a chemical equation for combustion reaction of the following hydrocarbon: 

Pentene 


Write a chemical equation for combustion reaction of the following hydrocarbon:

Hexyne


Arrange the halogens F2, Cl2, Br2, I2, in order of their increasing reactivity with alkanes.


The addition of HBr to 1-butene gives a mixture of products A, B and C

(A)
(B)
(C) CH3 – CH2 – CH2 – CH2 – Br

The mixture consists of:


Arrange the following hydrogen halides in order of their decreasing reactivity with propene.


Which of the following alkenes on ozonolysis give a mixture of ketones only?

(i) CH3 – CH = CH – CH3
(ii) \[\begin{array}{cc}
\ce{CH3 - C - CH = CH2}\\
|\phantom{.......}\\
\ce{CH3}\phantom{....}
\end{array}\]
(iii)
(iv) \[\begin{array}{cc}
\phantom{...................}\ce{CH3}\\
\phantom{..............}/\\
\ce{(CH3)2 C = C}\\
\phantom{..............}\backslash\\
\phantom{...................}\ce{CH3}
\end{array}\]

In the presence of peroxide addition of HBr to propene takes place according to anti Markovnikov’s rule but peroxide effect is not seen in the case of HCl and HI. Explain.


An alkene 'X' on ozonolysis produces two moles of isovaleraldehyde. Predict the IUPAC name of the alkene. 


Which of the following reagent is used for the following reaction?

\[\ce{CH3CH2CH3 ->[?] CH3CH2CHO}\]


The major product formed in the following reactions is:


Select schemes A, B, C out of

(I) acid catalysed hydration

(II) HBO

(III) oxymercuration-demercuration


Propene, \[\ce{CH3 - CH = CH2}\] can be converted to 1-propanol by oxidation. Which set of reagents among the following is ideal to effect the conversion ______.


In the presence of peroxide, HCl and HI do not give anti-Markovnikov's addition of alkenes because ______.


Identify the correct reagents that would bring about the following transformation.


Which of the following is the key step in the manufacture of sulphuric acid?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×