Quiz 7: Grignard Synthesis of Triphenylmethanol - Pt. 2 Flashcards
Which of the following describes the bond between C & Mg in the Gringard reagent?
A. Nonpolar
B. Mg has a partial negative charge; C has a partial positive charge.
C. Mg has a partial positive charge; C has a partial negative charge.
D. No bond between Mg & C
C
Howe many signals are expect for the 1H and 13C NMR spectra of the Gringard final product (triphenylmethanol)?
A. 1H NMR = 4 signals; 13 C = 5 Signals
Which is the side product and how is it removed from the product?
A. petroleum ether
B. Mg-Mg
C. Mg-Br-Mg-Br
D.
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How many moles of phenylmagnesium bromide react with 1 mole of benzophenone to form triphenylmethanol?
A. 1.5
B. 1
C. 3
D. 2
B. 1
Sort from least polar to most polar.
A. hexane B. methanol C. diethyl ether
A. A < B < C
B. A < C < B
B
What is the role of HCl?
A. HCl protonates the alkoxide ion & reacts with excess Mg/Gringard reagent
B. HCl reacts with residual alkyl halide to eliminate & purify the ketone
A
During the HCl work up, what causes bubbling?
A. CO2 evaluation
B. O2
C. H2
D. Boiling excess bromobenzene
C
What is the expected difference for the TLC results between the starting reagent and the final product of the Gringard synthesis?
product more polar/has a lower Rf
Is this a possible Gringard reaction?
*See Number 9 on Quiz 7
A. Yes, it is a good way to product diols.
B. No, secondary alcohols can’t be produced via Gringard synthesis
C. No, aldehydes can’t be used in Gringard synthesis
D. No, there will be acid/base reaction in Gringard synthesis
D
2.30 g of phenyl magnesium bromide (MW = 181.31 g/mol) reacts with 1.09 g of benzophenone (MW = 182 g/mol). How many ????
A. 1.00
B. 1.60
C. 2.05
D. 0.314
C
In a Gringard reaction, the nucleophilie is a(n):
A. carbonyl
B. ylide
C. organometallic reagent
C
