Chemistry CHEM S-20ab Lecture Notes - Lecture 16: Ketone, Sulfuric Acid, Aryne

Drug designers often start with a “lead compound” that exhibits a mild therapeutic effect. The designers chemically modify the molecule in multiple ways and then test each variant to see whether it works better than the original lead compound. The modifications often include the addition or removal of functional groups. To mimic this process, start with the molecule shown below and perform the chemical modifications listed below (Steps 1 – 4).

         Step 1: Remove the entire carboxyl group and replace it with a hydrogen atom.

         Step 2: Replace two of the hydrogen atoms in the hexagonal ring structure with hydroxyl groups (note that only one hydroxyl group can be attached to a given carbon atom).

         Step 3: Locate the amino group that is not part of a ring structure and replace one of its hydrogen atoms with a CH₃ group.

         Step 4: Add a CH₃ group to one of the hydroxyl groups to form an ether linkage.

(a) Paste in a drawing of the final molecular structure. 

(b) What is the net (overall) charge of the original molecule at neutral pH? What is the net charge of the fully modified molecule (the one you drew) at neutral pH?

Please help with the mechanism for this reaction below:

I need help with this question from book I don't understand how ch3(ch2)5Br became ch3(ch2)Br I don't understand what reaction took place I have also highlighted in red to show please show step by step to end so I can understand.