Quiz 8: Wittig Reaction Flashcards
DCM * H2O are added and micro extracted by…
A. bottom layer removed & remaining layer extracted 2 more times with DCM
B. top layer removed & remaining layer extracted 2 more times using DCM
C. bottom layer removed & top washed 2 times with H2O
D. treated with sodium sulfate to remove H2O
A
What determines stereochemistry (cis/trans) of the Wittig product in 1H NMR spectrum?
A. coupling constants
B. chemical shifts
C. integration values
D. splitting values
A
Which structures have J values between 11-18 Hz?
*See Question 3 from Quiz 8
I & III
What is the electrophile in the Wittig reaction?
A. carbonyl
B. ylide
C. organometallic reagent
D. carbocation
A
What is the splitting pattern of this non aromatic proton?
*See Question 5 from Quiz 8
A. singlet
B. doublet
C. triplet
D. quartet
B
Which of the following is true?
I. Wittig reaction forms 2 C-C bonds, both sigma and pi bonds as well as a para by-product
II. Wittig reaction forms 2 C-C bonds; both pi bonds as well a para by-product
III. Wittig reaction forms 2 C-C bonds; 1 pi and 1 sigma bond as well as a para by-product
IV. Wittig reaction has an oxaphosphorane intermediate that is a 4-membered ring
A. only I
B. only III
C. only II, IV
D. only III, IV
D
If you integrate Ha as 1, what is the total integration value?
*See Question 7 on Quiz 8
A. 8
B. 9
C. 14
D. 15
C
Students add boiling isopropanol during recrystallization but the mixture continues to be cloudy. What steps should be taken next?
A. heat sample to a higher temperature
B. solution is obviously saturated; therefore, put on ice
C. remove solvent to form more crystals
D. hot gravity filtration
D
What are the expected TLC spots if testing the reactant, mixture of reactant & product, and product for the Witting reaction?
*See Question 9 on Quiz 8
B
What reactant reacts with NaOH?
*See Question 10 on Quiz 8
benzylbiphenyl-phosphonium chloride
