Quiz 6: Grignard Synthesis of Triphenylmethanol - Pt. 1 Flashcards
Why was the drying tube filled with CaCl2 in the Gringard synthesis?
helps maintain anhydrous conditions
of signals in 13C NMR of Grignard product?
5
Why is it important to maintain volume of diethyl ether suggested during Grignard reactant generation?
A. If the concentration of alkyl halide gets too high, there can be undesirable side rxns.
B. Diethyl ether solubilizes the product shifting the equilibrium to the right.
A
of signals expected in 1H NMR of Grignard?
4
Grignard rxn of ketone w/ one equivalents of Grignard reagent yields:
A. 2 degree alcohol
B. An ester
C. 3 degree alcohol
D. Ketone
C
Alkylation of 1,4-dimethoxybenzene used approx 4:1 equiv of t-butanol to 1,4-dimethoxybenzene. Why did the rxn not produce a tetra-substituted product.
A. Compound already stabilized by resonance
B. Steric hindrance from bulky t-butyl groups prevented further alkylation
C. Lack of bulky groups hear rxn site prevents further alkylation
D. Disubstituted compound less electrophilic than starting material.
B
Which of the following are all true?
I. Magnesium rxn alkyl halide is exothermic
II. If trouble forming Grignard reagent, add iodine crystals
III. Grignard reagent can react with O2
IV. Moisture sensitive reaction
All of the above
Addition of Mg metal to aromatic yields:
A. Bromide nucleophile
B. Aromatic electrophile
C. Carbon nucleophile
D. Mg electrophile
C
What is the electrophile in this week’s Grignard rxn?
Ketone
Which is true?
I. Grignard reagents (RMgX) can react as both base and nucleophile
II. Grignard reagents contain very polar carbon-metal bonds where carbon bears a partial positive charge
III. Reaction of Grignard reagent with carbonyl compound can produce a 1,2,3 degree alcohol depending on choice of carbonyl compound.
A. Only 1
B. Only 2 & 3
C. Only 1 & 3
D. All are true
C
After 1,4-dimethoxybenzene alkylation- TLC conducted Rf value of starting material was less than Rf of product. What is the reason for this?
A. Addition of 2 alkyl groups makes the product more polar
B. Addition of 2 alkyl groups makes the product less polar
C. Addition of 2 alkyl groups has no effect on polarity
D. Addition of 2 alkyl groups made the product’s stationary phase interaction more favorable than the starting material’s stationary phase interaction.
B
