Write the structure of a diene that would be very reactive in a Diels-Alder reaction: e.g. cyclopentadiene, or 1,3cyclohexadiene…
Write the structure of a di ene that would NOT react in a Diels-Alder reaction: e.g. 1,4-cyclohexadiene, or Z,Z-2,4-hexadiene
Incorrect answers:
•1,3-butadiene (does react, but slower)
•Cyclobutadiene dimerizes by a Diels-Alder reaction at 35 K!

Today:
Conclusion of Grignard. TLC
Next Tuesday, 3/16 :
In LabLecture :
Your Questions. Introduction to Unknowns.
In Lab:
Midterm, 2:10 – 4pm, in your lab

Midterm Exam (100 points)
Tuesday, March 16, 14:10 - 16:00 in your lab
Five problem sets.
Covers the material of labs and lab lectures during the first half of the semester (including Grignard/TLC). The exam will address chemical structures and reactions, procedures and reasons for them, calculations, problem sets, spectra related to our experiments, practice questions, lab lectures.
See sample exam for style of problems.
Rules:
Cell phones off and in your pack.
Do bring a calculator, but not a "computer". No sharing ...
Do not leave the room during the exam.
No extra note paper; use back of pages if necessary.
Please no questions during exam (unless you discover a serious mistake). You can write: "if I understand the question this way ..."
No "late" exams... A midterm not taken earns the grade "F".
Start studying early.
Read questions carefully.
Proofread!

Grignard
Our multistep synthesis of triphenyl methanol , starting with the synthesis of our Grignard reagent :
1
Today: Steps 1 and 2
Water-free!
2
Grignard
Adduct
Water-free!
3
Evaluation by TLC

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

What is the purpose of adding dilute sulfuric acid to the adduct mixture?
Why do we add ligroin to the ether before evaporating to obtain our product?

What type of reactions are Grignard reactions?
How could you synthesize triphenyl methanol from a ketone , using our Grignard reagent?
How could you synthesize triphenyl methanol by a different method (not Grignard)?

TLC
Thin Layer Chromatography is an example of chromatography.
• 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?

Next time (3/16):
Your questions…
Introduction to Unknowns
In Lab:
Midterm, 2:10 – 4pm