Rules of the Day 320N

SNOW DAY!!! UT is closed. Watch the recorded lecture from 2024 by clicking here.

Click here for a copy of the lecture notes I wrote in class

Click here for a copy of the handouts I used in class today

Featured Golden Rule of Chemistry: 9. Functional groups react the same in different molecules.

1. Organolithium, Grignard and Gilman reagents react as nucleophiles with epoxides at the less hindered site to give new carbon-carbon bonds. Carbon-carbon bond forming!

2. Gilman reagents are very useful because they react as nucleophiles with primary haloalkanes, vinylic halides, aryl halides (halogen atom attached to sp2 carbon of a double bond including benzene rings) and epoxides at the less hindered site to give new carbon-carbon bonds! (Note that organolithium and Grignard reagents do not react with primary haloalkanes, vinylic halides or aryl halides, just epoxides) Carbon-carbon bond forming!

3. Alkyllithium reagents are the most basic limiting their use, Grignard reagents will deprotonate anything more acidic than an alcohol and Gilman reagents are the least basic, allowing them to react with primary haloalkanes, vinyl halides and aryl halides to make C-C bonds. Click here to watch a video that explains Gilman reagents in more detail.

4. When doing synthesis problems you need to count carbons in the starting materials and products (to figure out if new C-C bonds are formed and if so, where), work backwards (start by determining what was the last reaction used to make the product, then continue going backwards until you connect to the starting materials) and use your Key Recognition Elements (KREs) to identify important structural features of the products that reveal what reactions were used to create them.

5. You are responsible for learning the nomenclature of aldehydes and ketones. Refer to Section 16.2

6. The most important feature of carbonyl groups is that the carbon-oxygen double bond is highly polarized, with a partial positive charge on the carbon atom and a partial negative charge on the more electronegative oxygen atom. From this description alone it is clear that nucleophiles will attack the carbon carbon atom (while C=O pi bond breaks) and Lewis acids or protons will react with the carbonyl oxygen atom. Time capsule: Strong base can remove a hydrogen on carbon atoms adjacent to carbonyl groups to give enolates.

7. The reactions of carbonyl compounds with nucleophiles occur according to four basic mechanism, we will call Mechanism A - D. The differences depend on when or if protons bond to the oxygen atom, and whether there is a leaving group attached to the carbonyl group.

8. Grignard reagents add to aldehydes and ketones to give tetrahedral alkoxide intermediates (can be isolated). These alkoxides are protonated when the chemist opens the flask and adds acid to give alcohols. Mechanism A. Carbon-carbon bond forming!

Homework:

Read: Sections 16.5, 16.6, 16.10 and 16.11 in the ebook textbook (skip 16.7-16.9 for now). This text is part of the Longhorn Textbook access program.

If you are new to my class, you might want to take my old CH320M/CH328M final (from 12-10-22). This will give you a calibration regarding your preparation for this class. Click here for a copy of the old CH320M/CH328M final.My class average on this exam was right around 79% on this final. (GREAT JOB shout out to my Fall of 2024 class by the way!!!) Click here for a copy of the same final exam with answers.

Take the Daily Quiz 3 before 10 PM tomorrow. Click here to access the quiz. These quizzes are designed to review the important material from today's lecture. Together, they will count as 3% of your final grade.

Finish working on the Homework Problem Set 1, due at 10 PM on Wednesday, Juanuary 22. Click here to access the Homework Problem Set 1. Note there are NO AKTIV LEARNING QUESTIONS THIS WEEK. Homeworks will be worth 10% of your final grade (20% from the Aktiv Learning and 80% from the Gradescope portions of the homework).

Click here for directions for how to use Gradescope