Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chem 353 > Chapter 18 > Flashcards

Chapter 18 Flashcards

1
Q

Secondary alcohol to ketone

A

Grignard + aldehyde 1)ether and h3o+ = aldehyde 2)Na2Cr2O7 and H2SO4 = ketone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Primary alcohol to aldehyde

A

Primary aclohol + PCC (oxidizing agent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Allene to keto/ald

A

1)O3 2) (CH3)2S ozonolysis followed by reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Acyl halide to ketone or aldehyde

A

1) AlCl3 2)H2O acylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are aldehydes more reactive than ketones?

A

Sterics- aldehyde H provides less hindrance than methyl group of ketone

Electronics- methyl group stabilizes cation on ketone, aldehyde cation is less stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the product of a carboxylic acid plus Li-R?

A

Ketone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the product of a nitrile and an organolithium?

A

Ketone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do you add to an acid chloride to make a ketone?

A

Lithium cuprate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why does a curate only add once to an acid chloride unlike organolithium?

A

Reacts via the halogen, not the carbonyl.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you make an aldehyde from an acid chloride?

A

Add a mild reducing agent like lithium aluminum t-butoxy hydride (LiAlH(O-t-Bu)3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you make an aldehyde from an ester?

A

DIBAL-H and cold temp. Splits at C-OR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do aldehydes and ketone exist as in water?

A

Hydrates - germinal diols, but ketone prefers to stay in ketone form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What catalyst is necessary for acetal formation and why?

A

Acid. B/c the OH of the hemiacetal is a poor leaving group, turning it to water makes it a good one, and the addition of the second O-R group can occur.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What type of reactant is needed to create a cyclic acetal?

A

A diol.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can acetals be used as protecting groups?

A

Protection of a more reactive aldehyde part of a molecule allows for restriction of other reactions to the ketone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What reactants are used, other than toxic HCN, to form cyanohydrins?

A

KCN/H2O/NaOH or NaCN/H2O/NaOH

17
Q

What type of amine is reacted with a ketone to form an imine?

A

Primary amine

18
Q

What is the ideal pH for imine formation and why?

A

4.5 - not too basic so there is enough acid to catalyze, and not too acidic so amine isn’t protonated and made non-nucleophilic.

19
Q

What is N2H4 used for?

A

Wolff-Kishner reduction of ketones. When reacted with a ketone, forms a hydrazone which can be reduced to an alkene

20
Q

What is the product of C=-N-R reacted first with organolithium, and second with H3O+?

A

First forms an imine, which is then hydrolyzed to form a ketone.

21
Q

Why does only a single addition occur when a nitrile reacts with a grignard?

A

Excess grignards is destroyed during the reaction.

Chem 353 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions