13. Alcohols and Carbonyl Compounds

What is the product of the reaction?

What is the product of the reaction?

What is the product of the reaction?

(•••) Draw a mechanism for the following oxidation reactions.

(a) <IMAGE>

Predict the product of the following oxidation reactions.

(a) <IMAGE>

(•••) A chemist attempted to oxidize a primary alcohol to a carboxylic acid using chromic acid. The product shown was obtained as a major component in the mixture. Suggest an arrow-pushing mechanism that accounts for its formation. [Think about what chromic acid would normally do to a phenol and make a list of bonds formed and bonds broken.]

Predict the product of the following oxidation reactions.

(d) <IMAGE>

Predict the product of the following reactions.

(b) <IMAGE>

(•••) Draw a mechanism for the following oxidation reactions.

(b) <IMAGE>

Fill in the missing reactant, reagent, or product for each of the following oxidation reactions.

(b) <IMAGE>

Though ketones, like aldehydes, are in equilibrium with a hydrated form, they cannot be further oxidized. Why?

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Identify the alcohols that would undergo oxidation to produce the following carbonyl compounds.

(a) <IMAGE>

Fill in the missing reactant, reagent, or product for each of the following oxidation reactions.

(a) <IMAGE>

Unfortunately, the use of NMO creates an additional green chemistry problem. What is the problem and how might it be solved? [Hint: See Chemistry in Context 13-E.]

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (ix) PCC; (x) H₂CrO₄ , H₂O. If no reaction occurs, write 'no reaction.'  

(a) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (xi) HOCl, H₂O (xii) HIO₄. If no reaction occurs, write 'no reaction.'  

(a) <IMAGE>

(••••) THINKING AHEAD We explain in Chapter 24 that bisphenols can be oxidized to quinones. (a) Calculate the oxidation numbers of C1 and C₂ in going from reactant to product. (b) Provide a mechanism for this transformation. [The reaction begins like the alcohol oxidations of Section 13.9.]

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In Assessment 13.48, identify the individual step that represents the general mechanism for all alcohol oxidation reactions.

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(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (i) SOCl₂ ; (ii) PBr₃ ; (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; (v) 1. TsCl, Et₃N 2. NaOt-Bu (vi) H₂SO₄ (vii) HCl; (viii) HBr; (ix) PCC; (x) H₂CrO₄ , H₂O (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(c) <IMAGE>

In light of Figure 24.22, provide a mechanism by which para-dihydroxybenzene is oxidized to para-quinone.

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Assessment 24.22 asked why meta-dihydroxybenzene could not be oxidized to meta-quinone. The attempted oxidation instead gives rise to three different quinone products. Suggest a mechanism for the formation of each.

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(•••) Draw a mechanism for the following oxidation reactions.

(d) <IMAGE>

(•••) Draw a mechanism for the following oxidation reactions.

(c) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (ix) PCC; (x) H₂CrO₄ , H₂O. If no reaction occurs, write 'no reaction.'

(o) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(o) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(f) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (ix) PCC; (x) H₂CrO₄ , H₂O If no reaction occurs, write 'no reaction.'

(f) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (ix) PCC; (x) H₂CrO₄ , H₂O If no reaction occurs, write 'no reaction.'

(k) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(k) <IMAGE>

(••) Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(c) <IMAGE>

(a) Based on Figure 24.23, explain why meta-dihydroxybenzene is not oxidized to meta-quinone.

(b) If a meta-quinone is not produced, what would you expect the product of the oxidation of meta-dihydroxybenzene to be? [We'll learn the answer to part (b) in Assessment 24.23.]

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Predict the product of the oxidation reactions shown.

(b) <IMAGE>

If there is no water present, the hydrate of an aldehyde cannot form. Could an aldehyde itself (not the hydrate) be oxidized to a carboxylic acid? Why?

In Hinkley, the cleanup continues today. In one process PG&E is using to mitigate the chromium(VI) toxicity, ethanol is injected into the soil. How would this reduce the chromium(VI) contamination?

Identify the alcohols that would undergo oxidation to produce the following carbonyl compounds.

(b) <IMAGE>

Identify the alcohols that would undergo oxidation to produce the following carbonyl compounds.

(c) <IMAGE>

(••) Oxidation of the phenol shown gives a single quinone product. Predict this product and explain why it is the only one formed.

<IMAGE>

Predict the product of the following oxidation reactions.

(c) <IMAGE>

(••) Phenol oxidation can be coupled with other reactions to form new C―C bonds using reactions studied previously. Predict the product of the following series of reactions.

(a) <IMAGE>

The intermediates for the Swern oxidation, a reaction introduced in Section 13.9.4, are shown. Provide the arrow-pushing mechanism that rationalizes the formation of each intermediate and the final product(s).

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What product is obtained from the reaction of each of the following alcohols with

a. H₂CrO₄?

1. 3-pentanol

2. 1-pentanol

3. 2-methyl-2-pentanol

What product is obtained from the reaction of each of the following alcohols with

c. the regents required for a Swern oxidation?

1. 3-pentanol

2. 1-pentanol

3. 2-methyl-2-pentanol

Predict the major products of the following reactions.

(c) <IMAGE of reaction>

Which of the following compounds would give

a positive Tollens test?

(Remember that the Tollens test involves mild basic

aqueous conditions.)

(d) CH3CH2CH2CH2CH(OH)OCH3

(e) CH3CH2CH2CH2CH(OCH3)2

(f) <IMAGE>

The following reaction involves a starting material with a double bond and a hydroxy group, yet its mechanism resembles a pinacol rearrangement. Propose a mechanism, and point out the part of your mechanism that resembles a pinacol rearrangement.

<IMAGE of reaction>

Predict the products formed by periodic acid cleavage of the following diols.

(c) <IMAGE>

(d) <IMAGE>

Predict the major products of the following reactions, including stereochemistry where appropriate.

(c) cyclooctanol +NaOCl/HOAC

(d) cyclopentylmethanol + CrO3・pyridine・HCl

Give the structure of the principal product(s) when each of the following alcohols reacts with (1) Na2Cr2O7/H2SO4, (2) PCC

(c) 4-hydroxydecanal

Give the structure of the principal product(s) when each of the following alcohols reacts with (3) DMP, and (4) 1 equiv NaOCl-TEMPO.

(c) 4-hydroxydecanal

Predict the major products of the following reactions, including stereochemistry where appropriate.

(e) cyclopentylmethanol + Na2Cr2O7/H2SO4

(f) cyclopentanol + HCl/ZnCl2

(g) n-butanol + HBr

Predict the major products of the following reactions.

(a) <IMAGE of reaction>

Predict the products of the reactions of

the following compounds with:

(1) chromic acid or excess sodium hypochlorite with acetic acid.

(2) PCC or NaOCl (1 equivalent) with TEMPO.

(d) cyclohexanone

Predict the products of the reactions of

the following compounds with:

(1) chromic acid or excess sodium hypochlorite with acetic acid.

(2) PCC or NaOCl (1 equivalent) with TEMPO.

(e) cyclohexane

Predict the products of the reactions of

the following compounds with:

(1) chromic acid or excess sodium hypochlorite with acetic acid.

(2) PCC or NaOCl (1 equivalent) with TEMPO.

(f) 1-phenylpropan-1-ol

Give the structure of the principal product(s) when each of the following alcohols reacts with (1) Na2Cr2O7>H2SO4, (2) PCC

(d) 1-methylcyclohexan-1,4-diol

Give the structure of the principal product(s) when each of the following alcohols reacts with (3) DMP and (4) 1 equiv NaOCl-TEMPO.

(d) 1-methylcyclohexan-1,4-diol

Under normal circumstances, tertiary alcohols are not oxidized.

However, when the tertiary alcohol is allylic, it can undergo

a migration of the double bond (called an allylic shift)

and subsequent oxidation of the alcohol. A particularly effective

reagent for this reaction is Bobbitt’s reagent, similar to TEMPO

used in many oxidations.

(M. Shibuya et al., J. Org. Chem., 2008, 73, 4750.)

<IMAGE of reaction>

Show the expected product when each of these 3° allylic

alcohols is oxidized by Bobbitt’s reagent

(c) <IMAGE>

(d) <IMAGE>

Predict the products you expect when the following starting material undergoes oxidation with an excess of each of the reagents shown below.

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(d) DMSO and oxalyl chloride

(e) DMP (periodinane) reagent

A chronic alcoholic requires a much larger dose of ethanol as an antidote to methanol poisoning than does a nonalcoholic patient. Suggest a reason why a larger dose of the competitive inhibitor is required for an alcoholic.

Show how you would convert 2-methylcyclopentanol to the following products. Any of these products may be used as the reactant in any subsequent part of this problem.

(a) 1-methylcyclopentene

(b) 2-methylcyclopentyl tosylate

(c) 2-methylcyclopentanone

Show how you would make each compound, beginning with an alcohol of your choice.

(d) <IMAGE>

(e) <IMAGE>

(f) <IMAGE>

Give the structures of the intermediates represented by letters in this synthesis.

<IMAGE of reactions>

Predict the major products of the following reactions.

(b) <IMAGE of reaction>

Chromic acid oxidation of an alcohol (Section 11-2A) occurs in two steps: formation of the chromate ester, followed by an elimination of H+ and chromium. Which step do you expect to be rate-limiting? Careful kinetic studies have shown that Compound A undergoes chromic acid oxidation over 10 times as fast as Compound B. Explain this large difference in rates. <IMAGE of reactions>

Predict the major products of the following reactions.

(d) <IMAGE of reaction>

Predict the products of the reactions of 

the following compounds with: 

(1) chromic acid or excess sodium hypochlorite with acetic acid.

(2) PCC or NaOCl (1 equivalent) with TEMPO.

(g) hexan-1-ol

(h) acetaldehyde, CH3CHO

Fill in the missing reactant, reagent, or product for each of the following oxidation reactions.

(c) <IMAGE>

Fill in the missing reactant, reagent, or product for each of the following oxidation reactions.

(f) <IMAGE>

Predict the reagents or reactant(s) necessary to complete the following syntheses.

(a) <IMAGE>

Show how you would synthesize the following carboxylic acids, using the indicated starting materials.

(e) p-xylene --> terephthalic acid