Organic Chemistry

Janice Gorzynski Smith

Chapter 17

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction - all with Video Answers

Educators

Chapter Questions

Problem 1

a. What orbitals are used to form the indicated bonds in $\alpha$ -sinensal?
b. In what type of orbitals do the lone pairs on 0 reside?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 2

Which carbonyl groups in the anticancer drug Taxol (Section 5.5) will undergo nucleophilic addition, and which will undergo nucleophilic substitution?

Colton K

Numerade Educator

Problem 3

Rank the compounds in each group in order of increasing reactivity toward nucleophilic attack.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 4

What alcohol is formed when each compound is treated with $\mathrm{NaBH}_{4}$ in $\mathrm{CH}_{3} \mathrm{OH}$ ?

Colton K

Numerade Educator

Problem 5

What aldehyde or ketone is needed to prepare each alcohol by metal hydride reduction?
a.
b.
c.

Nicole Krahulik

Nicole Krahulik

Numerade Educator

Problem 6

Draw the products formed when $\mathrm{CH}_{3} \mathrm{COCH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}$ is treated with each reagent: (a) LiAlH $_{4},$ then $\mathrm{H}_{2} \mathrm{O} ;$ (b) $\mathrm{NaBH}_{4}$ in $\mathrm{CH}_{3} \mathrm{OH} ;$ (c) $\mathrm{H}_{2}$ ( 1 equiv), $\mathrm{Pd}-\mathrm{C} ;$ (d) $\mathrm{H}_{2}$ (excess), Pd-C; (e) $\mathrm{NaBH}_{4}(\mathrm{excess})$ in $\mathrm{CH}_{3} \mathrm{OH} ;$ (f) $\mathrm{NaBD}_{4}$ in $\mathrm{CH}_{3} \mathrm{OH}$

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 7

Draw the products formed (including stereoisomers) when each compound is reduced with $\mathrm{NaBH}_{4}$ in $\mathrm{CH}_{3} \mathrm{OH}$.

Colton K

Numerade Educator

Problem 8

What carbonyl compound and CBS reagent are needed to prepare $X,$ an intermediate in the synthesis of ezetimibe (trade name Zetia), a drug that lowers cholesterol levels by inhibiting its absorption in the intestines?

Ian Kaigh

Numerade Educator

Problem 9

Draw a stepwise mechanism for the following reaction.

Colton K

Numerade Educator

Problem 10

Draw the structure of both an acid chloride and an ester that can be used to prepare each compound by reduction.

Ian Kaigh

Numerade Educator

Problem 11

Draw the products formed from LiAlH $_{4}$ reduction of each compound.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 12

What amide(s) will form each of the following amines on treatment with LiAlH $_{4}$ ?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 13

What product is formed when each compound is treated with either LiAlH $_{4}$ (followed by $\left.\mathrm{H}_{2} \mathrm{O}\right),$ or $\mathrm{NaBH}_{4}$ in $\mathrm{CH}_{3} \mathrm{OH} ?$

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 14

What product is formed when each compound is treated with either $\mathrm{Ag}_{2} \mathrm{O}, \mathrm{NH}_{4} \mathrm{OH}$ or
$$
\mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}, \mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{H}_{2} \mathrm{O} ?
$$

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 15

Review the oxidation reactions using $\mathrm{Cr}^{6+}$ reagents in Section $12.12 .$ Then draw the product formed when compound $\mathrm{B}$ is treated with each reagent.
a. $\mathrm{NaBH}_{4}, \mathrm{CH}_{3} \mathrm{OH}$
b. $[1] \mathrm{LiAlH}_{4} ;[2] \mathrm{H}_{2} \mathrm{O}$
c. PCC
d. $\mathrm{Ag}_{2} \mathrm{O}, \mathrm{NH}_{4} \mathrm{OH}$
e. $\mathrm{CrO}_{3}, \mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{H}_{2} \mathrm{O}$

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 16

Write the step(s) needed to convert $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Br}$ to each reagent:
(a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Li} ;$ (b) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr} ;$ (c) $\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{CuLi} .$

Colton K

Numerade Educator

Problem 17

Write the step(s) needed to convert $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Br}$ to each reagent:
(a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Li} ;$ (b) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr} ;$ (c) $\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{CuLi} .$

Colton K

Numerade Educator

Problem 17

Which of the following species represent organometallic compounds:
$\mathrm{BrMgC} \equiv \mathrm{CCH}_{2} \mathrm{CH}_{3} ;$ (b) $\mathrm{NaOCH}_{2} \mathrm{CH}_{3} ;$ (c) $\mathrm{KOC}\left(\mathrm{CH}_{3}\right)_{3} ;$ (d) PhLi?

Nicole Krahulik

Nicole Krahulik

Numerade Educator

Problem 18

Draw the product formed when each organometallic reagent is treated with $\mathrm{H}_{2} \mathrm{O}$.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 19

Draw the product of each reaction.

Nima Gharibi

Numerade Educator

Problem 20

Draw the products (including stereochemistry) of the following reactions.

Colton K

Numerade Educator

Problem 21

What Grignard reagent and carbonyl compound are needed to prepare each alcohol? As shown in part (d), $3^{\circ}$ alcohols with three different R groups on the carbon bonded to the OH group can be prepared by three different Grignard reactions.

Ian Kaigh

Numerade Educator

Problem 22

linalool (the Chapter 9 opening molecule) and lavandulol are two of the major components of lavender oil. (a) What organolithium reagent and carbonyl compound can be used to make each alcohol? (b) How might lavandulol be formed by reduction of a carbonyl compound? (c) Why can't linalool be prepared by a similar pathway?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 23

What Grignard reagent and carbonyl compound can be used to prepare the antidepressant venlafaxine (trade name Effexor)?

Ian Kaigh

Numerade Educator

Problem 24

Using protecting groups, show how estrone can be converted to ethynylestradiol, a widely used oral contraceptive.

Colton K

Numerade Educator

Problem 25

Draw the product formed when each compound is treated with two equivalents of $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{MgBr}$ followed by $\mathrm{H}_{2} \mathrm{O}$

Ian Kaigh

Numerade Educator

Problem 26

What ester and Grignard reagent are needed to prepare each alcohol?

Colton K

Numerade Educator

Problem 27

What organocuprate reagent is needed to convert $\mathrm{CH}_{3} \mathrm{CH}_{2}$ COCl to each ketone?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 28

What reagent is needed to convert (CH $_{3}$ ) $_{2} \mathrm{CHCH}_{2} \mathrm{COCl}$ to each compound?

Ali Azmy

Numerade Educator

Problem 29

Draw two different ways to prepare each ketone from an acid chloride and an organocuprate reagent.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 30

What carboxylic acid is formed from each alkyl halide on treatment with [1] Mg; [2] $\mathrm{CO}_{2}$; [3] $\mathrm{H}_{3} \mathrm{O}^{+} ?$

Colton K

Numerade Educator

Problem 31

What epoxide is needed to convert $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr}$ to each of the following alcohols, after quenching with water?

Ian Kaigh

Numerade Educator

Problem 32

Draw the product when each compound is treated with either (CH $_{3}$ ) $_{2}$ CuLi, followed by
$\mathrm{H}_{2} \mathrm{O},$ or $\mathrm{HC} \equiv \mathrm{CLi},$ followed by $\mathrm{H}_{2} \mathrm{O}$

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 33

Convert propan-2-ol $\left[\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHOH}\right]$ to each compound. You may use any other organic or inorganic compounds.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 34

Synthesize each compound from cyclohexanol, ethanol, and any other needed reagents.

Ian Kaigh

Numerade Educator

Problem 35

Draw the products formed when $A$ or $B$ is treated with each reagent. In some cases, no reaction occurs.
a.
b.
c.
d.
e.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 36

Devise a synthesis of each alcohol from organic alcohols having one or two carbons and any required reagents.

Ian Kaigh

Numerade Educator

Problem 37

Draw the product formed when pentanal (CH $\left._{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CHO}\right)$ is treated with each reagent. With some reagents, no reaction occurs.

Ronald Prasad

Numerade Educator

Problem 38

Draw the product formed when $\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2}\right)_{2} \mathrm{CuLi}$ is treated with each compound. In some cases, no reaction occurs.

Ian Kaigh

Numerade Educator

Problem 39

The stereochemistry of the products of reduction depends on the reagent used, as you learned in Sections 17.5 and $\underline{17.6 .}$ With this in mind, how would you convert 3,3 -dimethylbutan-2-one $\left[\mathrm{CH}_{3} \mathrm{COC}\left(\mathrm{CH}_{3}\right)_{3}\right]$ to: racemic 3,3 -dimethylbutan-2-ol $\left[\mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{C}\left(\mathrm{CH}_{3}\right)_{3}\right] ;$ (b) only $(R)-3,3-$ dimethylbutan-2-ol; (c) only (S)-3,3-dimethylbutan-2-ol?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 40

Draw the product formed when the $\alpha, \beta$ -unsaturated ketone $A$ is treated with each reagent.
a. $\mathrm{NaBH}_{4}, \mathrm{CH}_{3} \mathrm{OH}$
b. $\mathrm{H}_{2}$ ( 1 equiv), Pd-C
c. $\mathrm{H}_{2}$ (excess), Pd-C
d. $[1] \mathrm{CH}_{3} \mathrm{Li} ;[2] \mathrm{H}_{2} \mathrm{O}$
e. [1] $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr} ;$ [2] $\mathrm{H}_{2} \mathrm{O}$
f. $[1]\left(\mathrm{CH}_{2}=\mathrm{CH}\right)_{2} \mathrm{CuLi} ;[2] \mathrm{H}_{2} \mathrm{O}$

Ian Kaigh

Numerade Educator

Problem 41

Draw the products of each reduction reaction.

Colton K

Numerade Educator

Problem 42

Draw the product(s) formed when $A$ is treated with each reagent.
a. $\mathrm{NaBH}_{4}, \mathrm{CH}_{3} \mathrm{OH}$
b. LiAlH $_{4}$, then $\mathrm{H}_{2} \mathrm{O}$
c. $\mathrm{Ag}_{2} \mathrm{O}, \mathrm{NH}_{4} \mathrm{OH}$ $\mathrm{d} \cdot \mathrm{CrO}_{3}, \mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{H}_{2} \mathrm{O}$
e. PCC

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 43

Draw the products of the following reactions with organometallic reagents.

Ian Kaigh

Numerade Educator

Problem 44

Identify the product $\mathrm{X},$ formed by the reaction sequence shown. These steps were used in the synthesis of resiniferatoxin, the complex chapteropening molecule.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 45

Draw all stereoisomers formed in each reaction.

Timothy Gailey

Numerade Educator

Problem 46

Draw all stereoisomers formed in the following two-step reaction sequence.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 47

Explain why metal hydride reduction gives an endo alcohol as the major product in one reaction and an exo alcohol as the major product in the other reaction.

Ian Kaigh

Numerade Educator

Problem 48

A student tried to carry out the following reaction sequence, but none of diol A was formed. Explain what was wrong with this plan, and design a successful stepwise synthesis of $\mathrm{A}$.

Colton K

Numerade Educator

Problem 49

Identify the lettered compounds in the following reaction scheme. Compounds $\mathrm{F}, \mathrm{G},$ and $\mathrm{K}$ are isomers of molecular formula $\mathrm{C}_{13} \mathrm{H}_{18} \mathrm{O} .$ How could ${ }^{1} \mathrm{H}$ NMR spectroscopy distinguish these three compounds from each other?

Ian Kaigh

Numerade Educator

Problem 50

Several steps in the synthesis of optically active duloxetine, an antidepressant sold under the trade name Cymbalta, are shown. Identify the structure of intermediates $A-C$ and the final product duloxetine, including stereochemistry, in this reaction sequence.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 51

Draw a stepwise mechanism for the following reaction. Your mechanism must show how both organic products are formed.

Nicole Krahulik

Nicole Krahulik

Numerade Educator

Problem 52

Draw a stepwise mechanism for the following reaction.

Colton K

Numerade Educator

Problem 53

Draw a stepwise mechanism for the following reaction.

Colton K

Numerade Educator

Problem 54

Slow addition of organolithium reagent $A$ to $B$ afforded $C,$ an intermediate in the synthesis of the chapter-opening molecule, resiniferatoxin. Draw a stepwise mechanism for this process.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 55

Draw a stepwise mechanism for the following reaction.

Colton K

Numerade Educator

Problem 56

What amides will form each amine on treatment with LiAlH $_{4}$ ?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 57

What Grignard reagent and aldehyde (or ketone) are needed to prepare each alcohol? Show all possible routes.

Colton K

Numerade Educator

Problem 58

Procyclidine is a drug that has been used to treat the uncontrolled body movements associated with Parkinson's disease. Draw three different methods to prepare procyclidine using a Grignard reagent.

Ian Kaigh

Numerade Educator

Problem 59

What ester and Grignard reagent are needed to synthesize each alcohol?

Colton K

Numerade Educator

Problem 60

What organolithium reagent and carbonyl compound can be used to prepare each of the following compounds? You may use aldehydes, ketones, or esters as carbonyl starting materials.

Ian Kaigh

Numerade Educator

Problem 61

What epoxide and organometallic reagent are needed to synthesize each alcohol?

Colton K

Numerade Educator

Problem 62

Propose at least three methods to convert $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br}$ to $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{CH}_{3}$

Ian Kaigh

Numerade Educator

Problem 63

Synthesize each compound from cyclohexanol using any other organic or inorganic compounds.

Ian Kaigh

Numerade Educator

Problem 64

Convert benzene into each compound. You may also use any inorganic reagents and organic alcohols having four or fewer carbons. One step of the synthesis must use a Grignard reagent.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 65

Design a synthesis of each compound from alcohols having four or fewer carbons as the only organic starting materials. You may use any other inorganic reagents you choose.

Colton K

Numerade Educator

Problem 66

Devise a synthesis of each alkyne. You may use acetylene, benzene, organic halides, ethylene oxide, and any other required inorganic reagents.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 67

Devise a synthesis of each compound from cyclohex-2-enone and organic halides having one or two carbons. You may use any other required inorganic reagents.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 68

Devise a synthesis of (E)-tetradec-11-enal, a sex pheromone of the spruce budworm, a pest that destroys fir and spruce forests, from acetylene, $\mathrm{Br}\left(\mathrm{CH}_{2}\right)_{10} \mathrm{OH},$ and any needed organic compounds or inorganic reagents.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 69

An unknown compound $A$ (molecular formula $\mathrm{C}_{7} \mathrm{H}_{14}$ O) was treated with $\mathrm{NaBH}_{4}$ in $\mathrm{CH}_{3} \mathrm{OH}$ to form compound $\mathrm{B}$ (molecular formula $\left.\mathrm{C}_{7} \mathrm{H}_{16} \mathrm{O}\right)$ Compound $A$ has a strong absorption in its IR spectrum at $1716 \mathrm{~cm}^{-1}$. Compound B has a strong absorption in its IR spectrum at $3600-3200$ $\mathrm{cm}^{-1}$. The ${ }^{1} \mathrm{H}$ NMR spectra of $\mathrm{A}$ and $\mathrm{B}$ are given. What are the structures of $A$ and $B ?$

Nicole Krahulik

Nicole Krahulik

Numerade Educator

Problem 70

Treatment of compound E (molecular formula $\mathrm{C}_{4} \mathrm{H}_{8} \mathrm{O}_{2}$ ) with excess $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr}$ yields compound $\mathrm{F}$ (molecular formula $\left.\mathrm{C}_{6} \mathrm{H}_{14} \mathrm{O}\right)$ after protonation with $\mathrm{H}_{2}$ O. E shows a strong absorption in its IR spectrum at $1743 \mathrm{~cm}^{-1} . \mathrm{F}$ shows a strong IR absorption at $3600-3200 \mathrm{~cm}^{-1} .$ The ${ }^{1} \mathrm{H}$
NMR spectral data of E and F are given. What are the structures of E and F? Compound E signals at 1.2 (triplet, 3 H), 2.0 (singlet, 3 H), and 4.1 (quartet, $2 \mathrm{H}$ ) ppm
Compound $\mathrm{F}$ signals at 0.9 (triplet, $6 \mathrm{H}$ ), 1.1 (singlet, $3 \mathrm{H}$, 1.5 (quartet, 4 H), and 1.55 (singlet, 1 H) ppm

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 71

Reaction of butanenitrile $\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CN}\right)$ with methylmagnesium bromide (CH $_{3}$ MgBr), followed by treatment with aqueous acid, forms compound G. G has a molecular ion in its mass spectrum at $m / z=86$ and a base peak at $m / z=43 .$ G exhibits a strong absorption in its IR spectrum at $1721 \mathrm{~cm}^{-1}$ and has the ${ }^{1} \mathrm{H}$ NMR spectrum given below. What is the structure of G? We will learn about the details of this reaction in Chapter $19 .$

Nicholas Howard

Nicholas Howard

Numerade Educator

Problem 72

Treatment of isobutene $\left[\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{CH}_{2}\right]$ with $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CLi}$ forms a carbanion that reacts with $\mathrm{CH}_{2}=\mathrm{O}$ to form $\mathrm{H}$ after water is added to the reaction mixture. H has a molecular ion in its mass spectrum at $m / z=86,$ and shows fragments at 71 and $68 .$ H exhibits absorptions in its IR spectrum at $3600-3200$ and $1651 \mathrm{~cm}^{-1},$ and has the $^{1} \mathrm{H}$ NMR spectrum given below. What is the structure of H?

Colton K

Numerade Educator

Problem 73

Draw a stepwise mechanism for the following reaction.

Colton K

Numerade Educator

Problem 74

Design a synthesis of $(R)$ -salmeterol (Figure 17.3 ) from the following starting materials.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 75

Explain why the $\beta$ carbon of an $\alpha, \beta$ -unsaturated carbonyl compound absorbs farther downfield in the ${ }^{13} \mathrm{C}$ NMR spectrum than the $\alpha$ carbon, even though the $\alpha$ carbon is closer to the electron-withdrawing carbonyl group. For example, the $\beta$ carbon of mesityl oxide absorbs at 150.5 ppm, whereas the $\alpha$ carbon absorbs at 122.5 ppm.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 76

Identify $\mathrm{X}$ and $\mathrm{Y},$ two of the intermediates in a synthesis of the antidepressant venlafaxine (trade name Effexor), in the following reaction scheme. Write a mechanism for the formation of $\mathrm{X}$ from $\mathrm{W}$.

Ian Kaigh

Numerade Educator

Problem 77

Reaction of benzylmagnesium chloride with formaldehyde yields alcohols $\mathrm{N}$ and $\mathrm{P}$ after protonation. Draw a stepwise mechanism that shows how both products are formed.

Colton K

Numerade Educator

Problem 78

Draw a stepwise mechanism for the following reaction. (Hint: Conjugate addition can occur with heteroatoms as well as carbon nucleophiles.)

Ian Kaigh

Numerade Educator

Problem 79

Draw a stepwise mechanism for the following reaction of a Grignard reagent with a cyclic amide.

Colton K

Numerade Educator