Grignard Reaction With A Ketone: Triphenylmethanol
Megan Wierzbowski
Organic II Laboratory
Wed. 11-1:50
Title: Grignard Reaction with a Ketone: Triphenylmethanol Part 1
Objective: The goal of this experiment is to learn to make Grignard reagents. The reactions of the Grignard reagents with ketones form tertiary alcohols. These reagents are highly air- and moisture-sensitive materials. We will observe the formation of the Grignard reagents, which magnesium metal is transformed into organometallic salts.
Experimental Procedure: Our experiment was as followed as in our text “Microscale Organic Laboratory” by Mayo from pages 275-283. The following modifications were made:
We performed the experiment through and including Isolation of Product.
We followed the regular phenylmagnesium bromide preparation …show more content…
Calculations:
1. Theoretical Yield of triphenylmethanol
Questions:
1. Write a mechanism for the Grignard reaction of benzophenone with phenylmagnesium bromide. Be as complete as possible and show electron flow for all steps.
2. Explain the special role of ethereal solvents like diethyl ether in the formation of Grignard reagents.
3. Triphenylmethanol can be prepared from phenylmagnesium bromide via several different Grignard reactions. Identify two other electrophiles (aside from benzophenone) that will react with PhMgBr to produce triphenylmethanol. Include a balanced reaction scheme for each of your answers.
4. a) Under the same exact conditions of Experiment 16, reaction of 4-bromophenol, instead of bromobenzene, would NOT give the analogous 3° alcohol product. Why? (HINT: why were special precautions taken to ensure anhydrous conditions when performing the Grignard
Organic II Laboratory
Wed. 11-1:50
Title: Grignard Reaction with a Ketone: Triphenylmethanol Part 1
Objective: The goal of this experiment is to learn to make Grignard reagents. The reactions of the Grignard reagents with ketones form tertiary alcohols. These reagents are highly air- and moisture-sensitive materials. We will observe the formation of the Grignard reagents, which magnesium metal is transformed into organometallic salts.
Experimental Procedure: Our experiment was as followed as in our text “Microscale Organic Laboratory” by Mayo from pages 275-283. The following modifications were made:
We performed the experiment through and including Isolation of Product.
We followed the regular phenylmagnesium bromide preparation …show more content…
Calculations:
1. Theoretical Yield of triphenylmethanol
Questions:
1. Write a mechanism for the Grignard reaction of benzophenone with phenylmagnesium bromide. Be as complete as possible and show electron flow for all steps.
2. Explain the special role of ethereal solvents like diethyl ether in the formation of Grignard reagents.
3. Triphenylmethanol can be prepared from phenylmagnesium bromide via several different Grignard reactions. Identify two other electrophiles (aside from benzophenone) that will react with PhMgBr to produce triphenylmethanol. Include a balanced reaction scheme for each of your answers.
4. a) Under the same exact conditions of Experiment 16, reaction of 4-bromophenol, instead of bromobenzene, would NOT give the analogous 3° alcohol product. Why? (HINT: why were special precautions taken to ensure anhydrous conditions when performing the Grignard