Some compounds are given below.(Question no 45)

a. Which is the most stable?

b. Which is the least stable?

The stability of these compounds is determined by the presence of alpha H in Alpha carbon. The more alpha carbon, the more will be stability.

No of 𝜶-H = 7 No of 𝜶-H = 4.

No of 𝜶-H = 5 No of 𝜶-H = 5

No of 𝜶-H = 4 No of 𝜶-H = 5

So, from the above picture, we can say that structure 1 is the most stable one.

Now, both b and e have 4 alpha Hydrogens. So, the stability will be decided depending on the bulky groups and cis, trans, and geminal structures.

Between b and e, e has a geminal linkage whereas, b has trans linkage throughout the double bond. As the trans arrangement is more stable than the geminal, the geminal structure will be the least stable.