Your Questions ??

Your Questions ??

α-bromoethylbenzene

Answers to MiniQuiz 4:

α-dibromoethylbenzene: one singlet and groups of aromatics

Quartet 1:3:3:1 !

Score: 2*/2

Today:Today:

• “ “Esterification”Esterification”

• Grignard reactionsGrignard reactions

• MiniQuizMiniQuiz

• Next Tuesday, March 10: Conclusion of Grignard.

• MiniQuiz on today’s class

• Following Tuesday 3/17: Following Tuesday 3/17: Your questions. Introduction to Unknowns. Your questions. Introduction to Unknowns.

Midterm 2:10 – 4pm in your labMidterm 2:10 – 4pm in your lab

(5 Problems. Total: 100 Pts.) (5 Problems. Total: 100 Pts.) Do Sample Midterms (in eres file; password!). Do Sample Midterms (in eres file; password!).

Review/study labs with calculations and problems and our lab Review/study labs with calculations and problems and our lab lectures.lectures.

Methyl Benzoate Synthesis

An equilibrium! Keq=3.0

1. What are the advantages of "boiling under reflux”?

2. What was the purpose of each of the following extraction steps:

1. rinsing with water

2. then extracting with sodium bicarbonate solution

3. extracting with sat. sodium chloride solution?

3. In our extraction with ether, which was the organic layer, top or bottom?

4. What would the H-NMRs of methyl benzoate and of benzoic acid look like?

Our Esterification Procedure

Grignard • What is a "Grignard reagent“?

• Properties of Grignard reagents?

• Which products do you obtain from the reaction of a Grignard reagent with a carbonyl group followed by hydrolysis?

• from an aldehyde…from a ketone…from an ester… ?

• What type of a reaction is it ….?

• Reaction of RMgX with water…?

Victor Grignard found that, in the presence of ether, magnesium reacts with alkyl and aryl halides at room temperature to form organomagnesium compounds.

For this discovery he was awarded the 1912 Nobel Prize in Chemistry.

RMgX – Ether Complex

Chlorophyll a

CH 3OOC

N

N N

N

O

CH 3CH

Mg

CH 3

CH 2CH 3H3C

H3C

H

H H

OO

CH 2

• Grignard reagents are metal-organic compounds. Other examples of metal-organic compounds? Are there any in nature?

Grignard

Our multistep synthesis of triphenyl methanol, starting with the synthesis of our Grignard reagent:

Grignard Adduct

DRY!

DRY!

Write the structure of the product obtained if our Grignard reagent reacts with

a) water

b) methanol

c) benzoic acid

d) carbon dioxide

e) acetone

f) formaldehyde

Thin Layer Chromatography is an example of chromatography.

•Do you know other types of chromatography?

•What is common to all types of chromatography?

TLC

What is the moving phase, the stationary phase in our TLC?

What type of information do we expect from our TLC?

TLC

Next Tuesday:

Conclusion of Grignard.

MiniQuiz on today’s class!

MiniQuiz 5 Problems:

1) Draw the structure of a diene (your choice) that would work well in a Diels-Alder reaction.

2) Draw the structure of a dienophile that would work well in a Diels-Alder reaction.