Rules of the Day 4-16-07

Click here for today's first lecture sheet

Click here for today's second lecture sheet

1. Fused benzenoid compounds are aromatic no matter how many pi electrons they have.

2. You must learn many common names (pg. 818) and how to use ortho, para, and meta.

3. Knowing when to use phenyl vs. benzyl can be tricky!

4. Atoms with a positive charge, a negative charge or an unpaired electron are all highly stabilized by resonance when attached directly to an aromatic ring. Phenols are extra acidic because the phenoxide anion is resonance stabilized. It is important that you can draw all of the contributing resonance forms of the phenoxide anion, and thus you understand why the negative charge is on the ortho and para positions.

5. As the result of the benzyl radical stability, it is easy to carry out free radical halogenation of the benzyl position using X2 and light or heat.

6. Alkyl groups on benzene rings are oxidized all the way to carboxylic acids using Na2Cr2O7/H2SO4 (H2CrO4) as long as there is at least one benzyl hydrogen atom on that alkyl group.

7. Electrophilic aromatic substitution involves wicked strong electrophiles reacting with the aromatic pi system to create a resonance stabilized arenium ion intermediate that then loses a proton to give the substitution product.

Homework: Finish working on homework Set 9. Click here to download a copy. Read: Read 22.2 (again) Problems: 22.4-22.5, 22.7, 22.19, 22.20)