Solution Found!
Grignard reagents add to carbonate esters as they add to
Chapter 15, Problem 55SP(choose chapter or problem)
Grignard reagents add to carbonate esters as they add to other esters.
(a) Predict the major product of the following reaction.
\(\mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{O}-\mathrm{C}-\mathrm{O}-\mathrm{CH}_{2} \mathrm{CH}_{3}\)
\(\frac{(1) \text { excess } \mathrm{Ph} M g B r}{(2) \mathrm{H}_{3} \mathrm{O}^{+}}\)
(b) Show how you would synthesize 3 -ethylpentan-3-ol using diethyl carbonate and ethyl bromide as your only organic reagents.
*(c) Diethyl carbonate is a liquid reagent that is easy to handle. In contrast, phosgene is a highly toxic and corrosive gas. Show how you might use diethyl carbonate instead of phosgene to make Lexan®.. Also show how you might use diethyl carbonate instead of methyl isocyanate to make Sevin® insecticide.
Equation transcription:
Text transcription:
{CH}{3}{CH}{2}-{O}-{C}-{O}-{CH}{2}{CH}{3}
frac{(1){ excess }{Ph} M g B r}{(2){H}{3}{O}^{+}}
Questions & Answers
QUESTION:
Grignard reagents add to carbonate esters as they add to other esters.
(a) Predict the major product of the following reaction.
\(\mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{O}-\mathrm{C}-\mathrm{O}-\mathrm{CH}_{2} \mathrm{CH}_{3}\)
\(\frac{(1) \text { excess } \mathrm{Ph} M g B r}{(2) \mathrm{H}_{3} \mathrm{O}^{+}}\)
(b) Show how you would synthesize 3 -ethylpentan-3-ol using diethyl carbonate and ethyl bromide as your only organic reagents.
*(c) Diethyl carbonate is a liquid reagent that is easy to handle. In contrast, phosgene is a highly toxic and corrosive gas. Show how you might use diethyl carbonate instead of phosgene to make Lexan®.. Also show how you might use diethyl carbonate instead of methyl isocyanate to make Sevin® insecticide.
Equation transcription:
Text transcription:
{CH}{3}{CH}{2}-{O}-{C}-{O}-{CH}{2}{CH}{3}
frac{(1){ excess }{Ph} M g B r}{(2){H}{3}{O}^{+}}
ANSWER:Solution:
Here we have to complete the given chemical reaction
Step 1
(a) We have to predict the major product of the following reaction.
Diethyl carbonate on addition with excess Grignard reagent (PhMgBr) in acidic medium gives triphenylmethanol as major product.
(Diethyl carbonate) (Triphenylmethanol)
Mechanism:-
Diethyl carbonate on addition with Grignard reagent (PhMgBr) in acidic medium undergoes nucleophilic substitution reaction and form ethyl benzoate which again in presence of phenyl magnesium bromide undergoes nucleophilic substitution reaction and form benzophenone, this on nucleophilic addition reaction with Grignard reagent in acidic medium gives triphenylmethanol.
+ CH3CH2-OH + Mg(OH)Br
(Diethyl carbonate) (Ethyl benzoate)
(Ethyl benzoate) (Benzophenone) (Triphenylmethanol)