And now we have setup KB number 6.

Write down the reaction equation, reaction mechanism and energy diagram for the following

reactions.

And we have here these very nice reactions.

Okay let's see the first one.

This is hydrolysis of tapucanol and this reaction runs through a SNI mechanism or nucleophilic

substitution type 1.

As you already know from the reading, this SNI mechanism breaks the bond between the

carbon and the first nucleophilic substitution.

This first nucleophilic substitution would be the OH group.

Then a carbocation is produced, which serves as a transition state.

And finally, the second or the new nucleophilic substitution, this time chlorine, is used to

intervene the electrophilic substitution.

This means that this carbocation formation is our reaction limiting step.

And stability and production is very important for the reaction.

In this case, a polar protic solvent is used.

Polar means a high dipole moment, where these interactions with the positively charged carbocation

are benefited and thereby stabilize it.

Since these carbocations are so unstable, in general carbocations are very unstable,

everything that improves their stabilization, everything that improves their stabilization,

we accelerate the reaction speed.

Here we have the energy diagram of the reaction, which I have already explained in our task

Again, very briefly, what happens here, we have a polar solvent.

So a polar solvent in comparison to an unpolar solvent can push the transition state of the

reaction to a lower energy range.

And how does this happen?

By a better stabilization of the carbocation.

And the result is a lower reactivation energy and of course an increased reaction speed.

Here we have the second reaction.

This is a reaction between sodium iodide and bromobutane.

This reaction runs through an SN2 mechanism, which is a nucleophilic substitution second

type.

Here this bondage with the first nucleophile brom is not broken so quickly.

This means that the new nucleophile, in this case J, must attack my electrophilic on the

other side, i.e. on the opposite of the descending group brom.

And we then have a configuration where both the electrophilic and the nucleophilic are

involved in the transition state.

For this reaction, a polar but apoptic solvent is preferred.

This is important, polar but apoptic.

Since the solvent is apoptic, hydrogen bonds can be avoided between the solvent and my

sodium iodide and thus this transition state is favored.

We can better understand it with the energy diagram.

So, if the solvent is apoptic, strong interactions between the solvent and the sodium iodide

will take place.

These interactions will, as I said, form hydrogen bonds.

In other words, this means that my duct would be too much soluble in the solvent and this

necessary energy to reach the transition state would be too high, unfortunately.

Therefore, it is better if an apoptic solvent is used, for example, acetone.

Because the Student isn't much soluble.