Advices For Studying Organic Chemistry

Figure 6.12 Energy diagrams for highly exergonic and highly endergonic steps of
reactions.

7) The transition state of the first step in an SN1 reaction resembles to the product

of that step:

Step 1

H 3 C C

CH 3

Cl

CH 3

H 2 O H^3 C C

CH 3

Cl

CH 3

δ+ δ−

H 2 O H^3 C C

CH 3

CH 3

+ + Cl−

Reactant Transition state Product of step
Resembles product of step stabilized by three electron-
Because ∆G° is positive releasing groups

i) Any factor that stabilizes the carbocation ––– such as delocalization of the

positive charge by electron-releasing groups ––– should also stabilize the

transition state in which the positive charge is developing.

8) The activation energy for an SN1 reaction of a simple methyl, primary, or

secondary halide is so large that, for all practical purposes, an SN1 reaction does

not compete with the corresponding SN2 reaction.