4. Here is a mechanism: 2)3H3CH2CH2MgBr 4. a. Draw all possible +,, and formal charges on the reactants and reagents. (Hint: you should REDRAW them below) 4.b. Draw two plausible mechanisms that shows how two different products are formed 4.c. Which mechanism is the most plausible and why? Explain using your understandings of forces and interactions. Using your proposed mechanisms for question 3 and 4 explain why the nucleophilic ring opening (that's a hint) results in addition of the nucleophile at different carbons depending upon the reaction conditions and the nucleophile