Chapters 18.1-18.14- 15.5-15.7

Which of the following statements is true regarding compounds that contain both aldehyde and alcohol functional groups?

They are named as aldehydes with hydroxyl substituents.

Which transformation of the compound shown would prompt the use of an acetal to protect the carbonyl group?

Treatment with Mg in ether to form a Grignard reagent

What is the geometry of a carbonyl group?

Trigonal planar

The product that forms from nucleophilic addition of ______ to an aldehyde/ketone is classified as a cyanohydrin.

cyanide

The polarization of the carbonyl group causes the carbonyl C to be ______ and therefore susceptible to attack by ______.

electrophilic; nucleophiles

Whereas reaction of an aldehyde or ketone with a primary amine results in formation of an imine, reaction of an aldehyde or ketone with a secondary amine results in formation of a(n) ______.

enamine

True or false: The addition of H2O to a carbonyl compound only occurs under acidic conditions.

false

he common name for the aldehyde methanal (CH2O) is ______.

formaldehyde

The C=O group found in aldehydes and ketones is called the ______ group.

carbonyl

The cyano group (CN) of a cyanohydrin is readily hydrolyzed to a ______ group by heating with aqueous acid or base.

carboxyl, (-COOH)

Which of the following statements is true regarding the synthetic relevance of cyanohydrins?

Cyanohydrins are easily converted to carboxylic acids, which are versatile compounds.

What general suffix is used to indicate that a compound is an aldehyde? (Exclude compounds in which the aldehyde group is attached to a cycloalkane ring.)

-al

The correct suffix for naming an aldehyde in which the CHO group is attached to a ring is ______.

-carbaldehyde

The correct suffix used to designate a ketone is ______.

-one

What are the approximate bond angles about the C atom of a carbonyl group?

120

Which of the following provides a good protecting group for an aldehyde/ketone?

Acetal

The carbonyl carbon atom is more electrophilic under these conditions.

Acidic conditions

Select all the statements that correctly describe a Wittig reagent.

An organophosphorus reagent A species containing nucleophilic C

An acetal can be hydrolyzed to an aldehyde or ketone. Select the reagent/reaction condition that will achieve hydrolysis of an acetal.

Aqueous acid

Nucleophilic attack occurs as the first step under these conditions.

Basic conditions

Which of the following are typical solvents for use in a Wittig reaction?

Dimethyl sulfoxide Tetrahydrofuran

What are the strongest type of intermolecular forces present between molecules of 2-butanone (shown)?

Dipole-dipole interactions

Which conditions will allow aldehydes and ketones to more quickly reach equilibrium with their hydrated forms?

Dissolving the aldehyde or ketone in a basic solution Dissolving the aldehyde or ketone in an acidic solution

Select all the statements that apply to the reaction of a carbonyl compound with H2O in the presence of either acid or base catalyst.

H and OH add across the C-O π bond. The product is called a hydrate.

Select all conditions that will reduce an aldehyde or ketone to the corresponding alkane.

H2NNH2; KO-t-Bu Zn(Hg); HCl

Which of the following statements explains why HCN is not used as a reagent to prepare cyanohydrins?

HCN is a weak acid and will not yield enough free CN- to yield high amounts of cyanohydrins.

Which functional group results from the addition of a single equivalent of an alcohol to an aldehyde or ketone?

Hemiacetal

Which of the following is the intermediate in the formation of an imine by reaction of an aldehyde or ketone with a primary amine?

Hemiaminal

Which of the following is the major organic product of the condensation of ammonia or a primary amine with the carbonyl group of an aldehyde or ketone?

Imine

The product of a reaction of an alkynide with a ketone, followed by protonation, will have which of the following structural characteristics? (Select all that apply.)

It will be a tertiary alcohol. It will contain a triple bond.

Which of the following substrates will give good yields of a geminal diol when reacted with H2O in the presence of acid or base? (Select all that apply.)

Ketones containing electron-withdrawing groups Formaldehyde Aldehydes containing electron-withdrawing groups

Which of the following reagents are commonly used in nucleophilic addition of -CN to an aldehyde or ketone?

NaCN HCl

What is the major organic product obtained by treatment of propanal with potassium dichromate (K2Cr2O7) under acidic conditions?

Propanoic acid

Select the steps required (not necessarily in order) to generate a Wittig reagent.

Reaction of an alkyl halide with Ph3P (triphenylphosphine) Reaction of a phosphonium salt with a strong base

What type of molecule will react with an aldehyde or ketone to give an enamine?

Secondary amine

Which of the following options correctly describe the reactivity of the C=O carbon atom in aldehydes and ketones?

Since the carbonyl C atom is relatively uncrowded, reactions at this site often involve nucleophilic addition reactions. This carbon atom is electrophilic due to the polarization of the C=O bond.

What solvent is used when triphenylphosphonium salts are converted to ylides using an alkyllithium reagent as the base?

Tetrahydrofuran

Which of the following options correctly describe the mechanism of acetal formation from an aldehyde or ketone?

The alcohol acts as a nucleophile in the reaction. The first step of the reaction is protonation of the carbonyl O atom. A hemiacetal is formed as an intermediate.

Select all the structural features that determine the chemical and physical properties of aldehydes and ketones.

The carbonyl C is an electrophilic center. The C and O of the C=O group are sp2 hybridized. The C=O group is polarized.

true of numbering in an aldehyde?

The carbonyl C is numbered as the first carbon.

Which of the following options correctly describe the nature of the carbonyl carbon atom?

The carbonyl carbon atom has less electron density than the carbonyl oxygen atom. This carbon atom is an electrophilic center.

Which of the following statements best describes why hexafluoroacetone will be almost completely hydrated in water?

The trifluoromethyl groups are extremely electron-withdrawing, which destabilizes the carbonyl C.

When a primary amine reacts with an aldehyde or a ketone, the net result is that _____.

a C=O group is replaced by C=NR

Cyanohydrin formation occurs under ______ conditions; the reaction is readily reversible by treatment with ______.

acidic; base

A Grignard reagent reacts with an aldehyde or ketone to form a new carbon-carbon bond and give a(n) ______ as the product after protonation.

alcohol

Which of the following correctly identifies the transformation that occurs during the Wittig reaction?

aldehyde/ketone → alkene

In the Wittig reaction a(n) ______ is produced by reaction of an aldehyde/ketone with a Wittig reagent.

alkene

During imine formation, nucleophilic attack by the primary _____ at the carbonyl C results in addition, which is followed by ______ of H2O. The final step is deprotonation to give the imine.

amine; elimination

An imine is also known as a Schiff ______.

base

The compound CH3CH2CH2CHO is named

butanal

Reaction of a carbonyl compound with H2O results in the addition of H and OH across the C=O π bond, resulting in a product that has two OH groups on the former C=O carbon. This structure is called a(n) _______ diol; it is also known as a(n) _______.

geminal; hydrate

The species formed when an aldehyde or ketone reacts with one equivalent of alcohol is a(n)______.

hemiacetal

Acetal formation is reversible, and an acetal can therefore be ______ to the original aldehyde or ketone using aqueous ______.

hydrolyzed; acid

A cyclic hemiacetal is formed by intramolecular cyclization of an open-chain ______ aldehyde.

hydroxy

Addition of a primary amine to an aldehyde or ketone, followed by elimination of water, results in the formation of a(n) ______.

imine

Alkyl groups are electron releasing and will ______ the stability of a carbonyl group but will ______ the stability of the corresponding carbonyl hydrate (geminal diol).

increase; decrease

In nucleophilic additions to carbonyl groups, the nucleophile generally approaches the ______ hindered face of the carbonyl carbon.

less

Since O is ______ electronegative than C, the C=O is polarized and the C has ______ electron density than the O.

more; less

In the reaction of acetylenic organometallic reagents with aldehydes and ketones, the acetylide carbon acts as a(n) ______ and the carbonyl carbon acts as a(n)

nucleophile; electrophile

The large difference in electronegativity between oxygen and carbon makes the C=O bond of an aldehyde or ketone ______. Aldehydes and ketones have ______ dipole moments than alkenes.

polar; larger

Acetals are readily formed and hydrolyzed, as well as being inert to many reactions that aldehydes and ketones normally undergo. An acetal is therefore an ideal ______ group for an aldehyde/ketone that is present with other functional groups.

protecting

What is the hybridization of the oxygen atom of a carbonyl group?

sp2

The C atom of a carbonyl group is ______-hybridized, and thus the bond angles about the C atom are approximately ______ degrees.

sp2; 120

The sigma component of a C=O double bond is formed by overlap of an ______ -hybridized orbital from carbon and an ______ -hybridized orbital from oxygen.

sp2; sp2

Addition of a nucleophile to a carbonyl group will often result in the creation of a new stereogenic center. In some of these reactions, more of one stereoisomeric product is formed than the other. Such a reaction is said to be ______.

stereoselective

Acid- and base-catalyzed hydration of aldehydes and ketones occur through different mechanisms. Acid-catalyzed hydration occurs in ______ steps, whereas base-catalyzed hydration occurs in ______ steps.

three; two

An acetal is produced by reaction of an aldehyde or ketone with ______ equivalent(s) of a(n) ______.

two; alcohol

Ethylene glycol, HOCH2CH2OH, will react with an aldehyde or ketone to form an acetal. Since ethylene glycol has ______ OH group(s), it forms a(n) ______ acetal when reacted with a carbonyl compound.

two; cyclic

An acetal is a compound ______.

with one carbon singly bonded to two -OR groups