Reading and applying are two different things when it comes to chem for me. I'm a visual learner and not being table to see examples in my text of what the reagents do, stinks. I'll try again after my class today, it's due thurs
Unfortunately reading and applying is the only way to learn in chemistry.
I am going to give a little help to start you off because I don't agree with the first step of this reaction. This reaction actually does not work experimentally due to the unstable nature of formic anhydride.
I can see what the assignment setter is trying to do but they should have used an alternative reagent. Maybe you should question them on it. Ask if the Vilsmeier–Haack reaction would be a better method for preparation of methybenzaldehyde.
Ok so step one is a "Friedel Crafts" an electrophillic substitution reaction. Substitution can occur in one of three different positions. You need to work out which one would be most likely due to the presence of the methyl group.
The NMR of compound B will also identify which product is formed (don't forget that there is another chemical reaction before B is formed)
Please see attached Scheme.