Q3.

Question

Question: When phenylacetaldehyde ( C₆H₅CH₂CHO) is dissolved in with added DCl, the hydrogen atoms α to the carbonyl are gradually replaced by deuterium atoms. Write a mechanism for this process that involves enols as intermediates.

Step-by-Step Solution

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Answer

Answer

A mechanism for the process involving enols as intermediates is shown below.

1Step 1: Tautomers

Tautomers are structural isomers of chemical compounds that readily interconvert in an acidic or a basic medium in the presence of . The process of conversion of one tautomer into another is known as tautomerization. One such example is keto-enol tautomers.

2Step 2: Insertion of deuterium in the alpha carbon

The solvent that is used here is formed of deuterated water and acid. So, when the tautomerization process occurs, the deuterium replaces hydrogens in the alpha carbon. The detailed mechanism is shown below.

Representation of the possible keto-enol tautomers

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Other exercises in this chapter

Q1.

Question: Draw the enol or keto tautomer(s) of each compound.

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Q2.

Question: During the metabolism of glucose, glyceraldehyde 3-phosphate is converted to dihydroxyacetone phosphate by a process that involves two keto-enol tauto

View solution

Q5.

Question: Which C-H bonds in the following molecules are acidic because the resulting conjugate base is resonance stabilized?

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Q6.

Question: Rank the protons in the labeled CH2 groups in order of increasing acidity, and explain why you chose this order.

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