Organic II - Reaction of Aromatic Compounds

[StefanoFIU]

Homework Statement

The Attempt at a Solution

I want to recognize the Cl as a good leaving group. After leaving, I get the ionized form of the chloroazirine reactant. Then, I want to draw some resonance structures to move the charge around the ring.

I do not understand the role of propylmagnesium bromide (Grignard reagent?) or what to do next. Also I do not see the the reason why the "not observed" is not observed. Am I correct up until this point? I appreciate any help, preferably any tips that could lead me to the answer, thank you!

 

[StefanoFIU]

Now I'm thinking that the methyl on the bottom ring exerts an effect on the entire compound forcing the propyl chain to attach to the bottom carbon of the chloroazirine (demonstrated in the major product).

 

[StefanoFIU]

The compound is asymmetrical. The methyl group is an electron-releasing group which stabilizes the intermediate formed, in this case the ionized azirine (formed upon removal of the Cl leaving group). Thus, the 3rd resonance structure is more stable than the first and second structures. Therefore, we should not expect to form the "not observed" product.

If the above is true, then my only problem left is to understand why propylmagnesium bromide was chosen for this reaction.