Chapter 11, Problem 11.39SP

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

1. a. (R)-butan-2-ol+TsCI In pyridine
2. b. (S)-2-butyl tosylate+NaBr
3. c. cyclooctanol+NaOCI/HOAc
4. d. cyclopentylmethanol+CrO3·pyridine·HCl
5. e. cyclopentylmethanol+Na2Cr207/H2SO4
6. f. cyclopentanol+HCl/ZnCl2
7. g. n-butanol+HBr
8. h. cyclooctylmethanol+CH3CH2MgBr
9. i. potassium tert-butoxide+methyliodide
10. j. sodium methoxide+tert-butyliodide
11. k. cyclopentanol+H2SO4/heat
12. l. product from (k)+OsO4/H2O2, then HIO4
13. m. sodiumethoxide+1-bromobutane
14. n. sodiumethoxide+2-methyl-2-bromobutane
15. ○.      octan-1-ol + DMSO + oxalyl chloride
16. p. 4-cyclopentylhexan-1-ol + DMP reagent

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Tosyl chloride in pyridine as a reagent is used to convert alcohols into respective tosylate esters through retention of configuration.

Answer to Problem 11.39SP

The major product of the given reaction is $\left(R\right)\text{-sec-butyl}\text{4-methylbenzenesulfonate}$.

Explanation of Solution

The given reaction occurs between $\left(R\right)\text{-butan-2-ol}$ and $\text{TsCl}$ in pyridine. Tosyl chloride in pyridine as a reagent is used to convert alcohols into respective tosylate esters through retention of configuration.

The product of the given reaction is shown in Figure 1.

Figure 1

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Sodium bromide is used to convert the compounds of tosylate ester into respective bromide through inversion of configuration.

Answer to Problem 11.39SP

The major product of the given reaction is $\left(R\right)\text{-2-bromobutane}$.

Explanation of Solution

The given reaction occurs between $\left(S\right)\text{-2-butyl}\text{tosylate}$ and $\text{NaBr}$. Sodium bromide is used to convert the compounds of tosylate ester into respective bromide through inversion of configuration.

The product of the given reaction is shown in Figure 2.

Figure 2

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Sodium hypochlorite with acetic acid $\left(\text{NaOCl}/\text{HOAc}\right)$ is used to convert secondary alcohols into ketones.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{cyclooctanone}$.

Explanation of Solution

The given reaction occurs between cyclooctanol and $\text{NaOCl}/\text{HOAc}$. Sodium hypochlorite with acetic acid $\left(\text{NaOCl}/\text{HOAc}\right)$ is used to convert secondary alcohols into ketones.

The product of the given reaction is shown in Figure 3.

Figure 3

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The Jones reagent $\left({\text{CrO}}_3\cdot \text{pyridine}\cdot \text{HCl}\right)$ is used to convert primary alcohols into aldehyde.

Answer to Problem 11.39SP

The major product of the given reaction is cyclopentanecarbaldehyde.

Explanation of Solution

The given reaction occurs between cyclopentylmethanol and ${\text{CrO}}_3\cdot \text{pyridine}\cdot \text{HCl}$. The Jones reagent $\left({\text{CrO}}_3\cdot \text{pyridine}\cdot \text{HCl}\right)$ is used to convert primary alcohols into aldehyde.

The product of the given reaction is shown in Figure 4.

Figure 4

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The Jones reagent $\left({\text{Na}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}/{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\right)$ is used to convert primary alcohols into carboxylic acids and secondary alcohols into ketone.

Answer to Problem 11.39SP

The major product of the given reaction is cyclopentanecarboxylic acid.

Explanation of Solution

The given reaction occurs between cyclopentylmethanol and ${\text{Na}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}/{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$. The Jones reagent $\left({\text{Na}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}/{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\right)$ is used to convert primary alcohols into carboxylic acids.

The product of the given reaction is shown in Figure 5.

Figure 5

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The Lucas reagent $\left(\text{HCl}/{\text{ZnCl}}_2\right)$ is used to convert secondary and tertiary alcohols into alkyl chloride.

Answer to Problem 11.39SP

The major product of the given reaction is chlorocyclopentane.

Explanation of Solution

The given reaction occurs between cyclopentanol and $\text{HCl}/{\text{ZnCl}}_2$. The Lucas reagent $\left(\text{HCl}/{\text{ZnCl}}_2\right)$ is used to convert secondary and tertiary alcohols into alkyl chloride.

The product of the given reaction is shown in Figure 6.

Figure 6

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The halo acids like $\text{HBr,}\text{HCl}\text{and}\text{HI}$ are used for halogenations of alcohols.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{1-bromobutane}$.

Explanation of Solution

The given reaction occurs between $\text{n-butanol}$ and $\text{HBr}$. The halo acids like $\text{HBr,}\text{HCl}\text{and}\text{HI}$ are used for halogenations of alcohols.

The product of the given reaction is shown in Figure 7.

Figure 7

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The reaction of alcohols with Grignard reagent leads to the formation of adduct complex of Grignard.

Answer to Problem 11.39SP

The major product of the given reaction is magnesium bromide cyclooctylmethanolate.

Explanation of Solution

The given reaction occurs between cyclooctylmethanol and ${\text{CH}}_3{\text{CH}}_2\text{MgBr}$. The reaction of alcohols with Grignard reagent leads to the formation of adduct complex of Grignard.

The product of the given reaction is shown in Figure 8.

Figure 8

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Methyl iodide is used to convert an alkoxide into ether with removal of halo-salts.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{2-methoxy-2-methylpropane}$.

Explanation of Solution

The given reaction occurs between potassium tert-butoxide and methyliodide. Methyl iodide is used to convert an alkoxide into ether with removal of halogen salts.

The product of the given reaction is shown in Figure 9.

Figure 9

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Sodium methoxide is a strong base, used for the conversion of bulkier haloalkane into an alkene with removal of an alcohol.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{2-methyl-1-propene}$.

Explanation of Solution

The given reaction occurs between sodium methoxide and tert-butyliodide. Sodium methoxide is a strong base, used for the conversion of bulkier haloalkane into an alkene with the removal of an alcohol.

The product of the given reaction is shown in Figure 10.

Figure 10

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The sulphuric acid catalyzed reaction is used to convert alcohols into an alkene through dehydration and $\text{E1}$ (mostly) and $\text{E2}$ (primary alcohols) mechanisms.

Answer to Problem 11.39SP

The major product of the given reaction is cyclopentene.

Explanation of Solution

The given reaction occurs between cyclopentanol and ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}/\text{heat}$.

The sulphuric acid catalyzed reaction is used to convert alcohols into an alkene through dehydration and $\text{E1}$ (mostly) and $\text{E2}$ (primary alcohols) mechanisms.

The product of the given reaction is shown in Figure 11.

Figure 11

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Osmium tetra oxide $\left({\text{OsO}}_{\text{4}}\right)$ is used to convert alkenes into diols. The further reaction of diols with periodic acid leads to the cleavage of diols and formation of aldehydes or ketones.

Answer to Problem 11.39SP

The major product of the given reaction is glutaraldehyde.

Explanation of Solution

The given reaction occurs between cyclopentene (product from k) and ${\text{OsO}}_4/{\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$.then ${\text{HIO}}_{\text{4}}$. Osmium tetra oxide $\left({\text{OsO}}_{\text{4}}\right)$ is used to convert alkenes into diols. The further reaction of diols with periodic acid leads to the cleavage of diols and formation of aldehydes or ketones.

The product of the given reaction is shown in Figure 12.

Figure 12

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Sodium ethoxide is a strong base and used to convert haloalkanes into respective ether through ${\text{S}}_{\text{N}}2$ mechanism.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{1-ethoxy}\text{butane}$.

Explanation of Solution

The given reaction occurs between sodium ethoxide and $\text{1-bromobutane}$.

Sodium ethoxide is a strong base and used to convert haloalkanes into respective ether through ${\text{S}}_{\text{N}}2$ mechanism.

The product of the given reaction is shown in Figure 13.

Figure 13

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: Sodium ethoxide is a strong base and used to convert bulkier haloalkanes into respective alkenes.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{2-methyl-2-butene}$.

Explanation of Solution

The given reaction occurs between sodium ethoxide and $\text{2-methyl-2-bromobutane}$.

Sodium ethoxide is a strong base and used to convert bulkier haloalkanes into respective alkenes.

The product of the given reaction is shown in Figure 14.

Figure 14

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The Swern oxidation of alcohols to convert it into aldehydes are done by $\text{DMSO}$ and oxalyl chloride reagent.

Answer to Problem 11.39SP

The major product of the given reaction is octanal.

Explanation of Solution

The given reaction occurs between $\text{octan-1-ol}$, $\text{DMSO}$ and oxalyl chloride. The Swern oxidation of alcohols to convert it into aldehydes are done by $\text{DMSO}$ and oxalyl chloride reagent.

The product of the given reaction is shown in Figure 15.

Figure 15

Interpretation Introduction

To determine: The major product of the given reaction, including stereochemistry if appropriate.

Interpretation: The major product of the given reaction, including stereochemistry if appropriate is to be predicted.

Concept introduction: The $\text{DMP}$ reagent is used to convert primary alcohols into aldehydes and secondary alcohols into ketones.

Answer to Problem 11.39SP

The major product of the given reaction is $\text{4-cyclopentylhexanal}$.

Explanation of Solution

The given reaction occurs between $\text{4-cyclopentylhexan-1-ol}$, $\text{DMP}$ reagent. The $\text{DMP}$ reagent is used to convert primary alcohols into aldehydes and secondary alcohols into ketones.

The product of the given reaction is shown in Figure 16.

Figure 16