Ketones and Aldehydes - Chp 18

Question 1

Which is weaker regarding aromatic substitution reactions? Halogens or CH3?

Answer 1

Halogens

Question 2

2R-C=O (or C=O) group is named…

Answer 2

oxo

Question 3

The C=O bond of ketones is ______ (longer/shorter), ________ (stronger/weaker) and more ________ (less/more polar) than the C=C bond of alkenes

Answer 3

shorter; stronger; more polar

Question 4

As the number of R groups around the carbonyl carbon (C=O) increases, the reactivity of C=O __________ (increases/decreases).

Answer 4

decreases

Question 5

Increasing steric hindrance _________ (increases/decreases) reactivity towards nucleophiles.

Answer 5

decreases

Question 6

Nomenclature: For aldehydes you add an ____ suffix.

Answer 6

-al
ex. 2-chloropentanal

Question 7

Nomenclature: If CHO is bonded to a ring, you name the ring and add _____________.

Answer 7

carbaldehyde

Question 8

List order of priority.
alkane
carboxylic acids
alcohols
amides
alkyl halides
ketone
alkene
esters
alkyne
aldehydes
ether

Answer 8

carboxylic acids
esters
amides
aldehydes
ketone
alcohols
alkene
alkyne
alkane
ether
alkyl halides

Question 9

Nomenclature: OH group is named _______.

Answer 9

hydroxy

Question 10

Nomenclature: For ketones you add an ____ suffix.

Answer 10

“one”
ex. acetone

Question 11

Compounds that contain both a C-C double bond and a ketone are named as ________.

Answer 11

enones

Question 12

Compounds that contain both a C-C double bond and an aldehyde are named as ________.

Answer 12

enals

Question 13

What is a benzoyl group?

Answer 13

Benzene + C=O

Question 14

Name this group. CHO

Answer 14

methanoyl or formyl

Question 15

CH3C=O with a benzene is named what?

Answer 15

Acetophenone

Question 16

Which has a higher b.p? Ketone or aldehyde?

Answer 16

Ketone

Question 17

Why is the b.p of ketone and aldehyde lower than alcohols?

Answer 17

They can’t H bond to each other.

Question 18

PCC/Swern/DMP reacting with alcohols forms what?

Answer 18

An aldehyde.

Question 19

Alkene reacting with (1) O3 (2) (CH3)2S forms what?

Answer 19

A cleavage of the alkene (aldehyde + ketone) and (CH3)2S=O

Question 20

What reagents are used in the ozonolysis of alkenes?

Answer 20

(1) O3
(2) (CH3)2S

Question 21

Alkyne reacting with Hg2+, H2SO4 and H2O forms what?

Answer 21

A methyl ketone (CH3-C=O)

Question 22

What reagents are used in the hydration of alkynes?

Answer 22

Hg2+, H2SO4 and H2O
or
(1) Sia2BH and (2) H2O2, NaOH

Question 23

Alkyne reacting with (1) Sia2BH and (2) H2O2, NaOH forms what?

Answer 23

An aldehyde.

Question 24

A Grignard or organolithium reagent attacking the carbon of a nitrile forms what?

Answer 24

A ketone.

Question 25

Which compound exists to the greatest extent as it hydrates when dissolved in aq solution? Aldehyde or ketone? Does conjugation increase or decrease its extent?

Answer 25

Aldehyde; conjugation increases its extent.

Question 26

What increase the reactivity toward cyanohydrin formation w/ HCN or KCN and ketones?

Answer 26

Electron-withdrawing groups (ex. halogens).

Question 27

What reagent can reduce nitriles to aldehydes?

Answer 27

Aluminum hydride ex. LiAlH4, (i-Bu)2AlH

Question 28

Give the general formula for a hemiacetal.

Answer 28

OH-C-OR (C attached with an OH group and an OR group)

Question 29

Give the general formula for an acetal.

Answer 29

OR-C-OR (C attached to 2 alkoxy groups)

Question 30

Oxidizing aldehydes forms what product?

Answer 30

(Easily oxidized to...) carboxylic acids

Question 31

Which is more reactive? Aldehydes or ketones? Why?

Answer 31

Aldehydes b/c they are more polarized and has less steric hindrance compared to the 2 R groups on ketones.

Question 32

PCC oxidizes primary alcohols to ________ and secondary alcohols to _______.

Answer 32

aldehydes; ketones

Question 33

What reagents can oxidize a secondary alcohol to a ketone?

Answer 33

PCC K2Cr2O7, H2SO4, H2O

Question 34

Does lithium aluminum hydride reduce both carbonyls if a compound has 2 carbonyl groups?

Answer 34

Yes.

Question 35

Sodium borohydride (NaBH4) can reduce __________ to _________ (secondary/primary) alcohols and ___________ to _________ (secondary/primary) alcohols.

Answer 35

ketones; secondary; aldehydes; primary

Question 36

Can LiAlH4 reduce any carbonyl? Explain.

Answer 36

Yes b/c it is a very strong reducing agent. (Difficult to handle)

Question 37

Raney Nickel (Ni-H2) reacting with a carbonyl forms...

Answer 37

An alcohol group.

Question 38

What reagent is used in catalytic hydrogenation?

Answer 38

Ni-H2

Question 39

What reagent are used in Clemmensen reduction?

Answer 39

Zn(Hg), HCl and H2O

Question 40

Zn(Hg), HCl and H2O reacting with ketones or aldehydes forms...

Answer 40

An alkane. (Reduces carbonyl "twice" by adding Hs.)

Question 41

What reagents are used in Wolff-Kishner reduction?

Answer 41

N2H4, KOH and heat

Question 42

What is the hydrazone group?

Answer 42

-C=N-NH2

Question 43

Carbonyl reacting with N2H4 forms what?

Answer 43

A hydrazone.