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Ochem 2 > Ch:18 Aldehydes and ketones: Nucleophilic Addition Rxn > Flashcards

Ch:18 Aldehydes and ketones: Nucleophilic Addition Rxn Flashcards

1
Q

The more R groups on the carbonyl C, the _______ reactive the compound. What effect is this due to? 

A

Less, steric effects 

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2
Q

Are Aldehydes or ketones more reactive?

A

Aldehydes 

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3
Q

According to IUPAC how do you name aldehydes?

A
  • end in -al
  • the -e in the corresponding alkane name is replace with suffix -al
  • if the -CHO Group is bonded to a carbon in a ring, the aldehyde is named by using the name of the cycloalkane + the suffix carbaldehyde 
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4
Q

How do you name Unbranched aldehydes by their common name?

A

Root + aldehyde 

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5
Q

How do you name branched aldehydes by their common name?

A

-use Greek letters 

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6
Q

What are the rules for naming ketones according to IUPAC?

A
  • end in -one

- parent chain = longest carbon chain that contains the C double bond O group

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7
Q

How do you name ketones by IUPAC if the double bond O is attached to a carbon in a ring?

A

Replace the e in the cycloalkane name with -one

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8
Q

How do you name ketones by their common name?

A

Name the two R groups alphabetically and add the word ketone. 

Ex:Diethylketone

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9
Q

In the group priorities, does ketones or aldehydes have a higher priority?

A

Aldehydes

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10
Q

Aldehydes and ketones do not contain ___ groups . 

A

OH

  • as a result there’s no possibility of hydrogen bonding, They only have the VDW forces and dipole dipole interactions
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11
Q

Aldehydes and ketones have _______ MP and BP Then alcohols in carboxylic acids of comparable molar mass.

A

Lower

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12
Q

What ketones and aldehydes are soluble in organic solvents?

A

All sizes

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13
Q

Aldehydes and ketones with a number of carbons less than or equal to ____ Are soluble in water because of their ability to hydrogen bond with water.

A

5

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14
Q

For cyclic ketones, the -C=O Frequency ___________ As the number of carbon atoms decreases because of ring strain.

A

Increases

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15
Q

For conjugated systems IR:
Frequency __________ With increasing conjugation because the -C=O Any conjugate system has a partial single bond character due to resonance. 

A

Deceases

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16
Q

For H NMR, Alpha H is ______ and the H Double bonded to O is ______. 

A

2-2.5 delta

9-10 delta

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17
Q

Oxidation of primary alcohols is done with?

-produces an aldehyde

A

PCC

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18
Q

Reduction of Esters Is done with

-produces an aldehyde

A

DIBAL-H

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19
Q

Reduction of acid chloride is done with? 

-produces an aldehyde

A

LiAlH[OC(CH3)3]3

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20
Q

Hydroboration (Non-Markonikov) of Terminal alkynes is done with?

-produces an aldehyde

A
  1. BH3

2. H2O2,OH-

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21
Q

Ozonolysis: Oxidative cleavage of Alkenes is done with? 

-Produces an aldehyde

A
  1. O3

2. Zn, H2O or CH3SCH3

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22
Q

Oxidation of a secondary alcohol is done by?

Produces a ketone

A

K2Cr2O7
H3O+

O |

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23
Q

Reaction of Organocuprates with Acid Chlorides is done with? 

(produces a ketone)

A
  1. R’2 CuLi
  2. H2O
  3. (CH3)2CuLi
  4. H2O
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24
Q

Friedel-Crafts Acylation: Aromatic ketones is done with?

A

AlCl3

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25
Q

Mercury ration or hydration of an alkaline (Follows Markovnikov) Is done by?

(Produces a ketone) 

A

H2O, H2SO4

HgSO4

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26
Q

Ozonolysis: Oxidative cleavage of try and Tetrasubstituted Alkenes Is done by?

(produces ketones)

A
  1. O3

2. Zn, H2O or CH3SCH3

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27
Q

Non-Markonikov Hydroboration of internal alkynes is done by?

Produces two ketones

A
  1. BH3

2. H2O2, OH-

28
Q

Reaction of nitriles with R’MgX 

(Produces a ketone)

A
  1. R’MgX

2. H2O

29
Q

What are the two general kinds of reactions of aldehydes and ketones?

A
  • nucleophilic addition reactions at the carbonyl carbon (unit 10)
  • Reactions at the Alpha carbon. These reactions require a base (unit 14) 

See page 382

30
Q

In reactions at the Alpha Carbon, what is produced as an intermediate?

A

an enolate ion

31
Q

What are the organometalic reagents?

A

R’M = R’MgX, R’Li, HC triple bond C-Li

32
Q

What is the grignard’s reagent?

A

MgX

33
Q

What is needed for Addition of CN- In acidic media: Cyanohydrin formation?

A

NaCN

HCL

34
Q

What is needed for the hydrolysis of a cyanohydrin To lead to alpha-hydroxy carboxylic acid? 

A

H2O

H+ or OH-

35
Q

What is the Wittig reaction used to do?

A

Convert a ketone or aldehyde to an alkene

36
Q

What is the Cannizzaro reaction of Aldehydes?

A

It occurs with aldehydes and ketones with no alpha hydrogens (Formaldehyde and benzaldehyde) in NaOH or KOH. The aldehyde is oxidized and reduced at the same time. 

37
Q

What is disproportionation?

And what rxn is associated?

A

Oxidation and reduction at the same time

Cannizzaro reaction 

38
Q

What is needed for the addition of a primary means to aldehydes and ketones:Imines?

A

R’NH2
Mild acid

Produces an imine

C=N

Replace oh with NR2 And put a double bond between C1 and alpha carbon

39
Q

Addition of secondary a means to aldehydes and ketones. What is needed?
What is produced? 

A

R’2NH
Mild acid

An enamine

C=C

40
Q

What is needed for the hydration of aldehydes in acidic or alkaline media? 

A

H2O
H+ or OH-

Produces a gem-diol (hydrate)

41
Q

Thermodynamics of hydration: is the reaction reversible?

A

Yes, dose not reach equilibrium

42
Q

Thermodynamics of hydration: More stable reactants give ______ yields.

A

Small

43
Q

Thermodynamics of hydration:

Does having more alkyl groups Give a higher or lower yeild at equilibrium?

A

Lower

Alkyl groups (EDG) stabilize the carbonyl groups through inductive electron donation 

44
Q

Thermodynamics of hydration:

The presence of EDG in a compound leads to _______ yields at equilibrium. 

A

Small

45
Q

What is needed for the addition of alcohols to aldehydes and ketones:acetal products? 

A

Catalyzed by an acid such as p-toluenesulfonic acid (TsOH)

-Get OR groups instead of OH groups

Called a ketal when done with ketones and an acetal when with aldehydes

46
Q

Acetals of ethylene glycol produce cyclic acetals by what reagent?

A

HOCH2CH2OH ——> ethylene glycol

(OH on both ends)

47
Q

What is used to remove water to increase the yield? 

A

Dean-Stark trap

48
Q

What can be used to protect aldehydes and ketones from Being reduced?

A

Ethylene glycol: HOCH2CH2OH

49
Q

Hydroxy aldehydes exist mostly as

A

Cyclic hemiacetals = lactol 

50
Q

A cyclic hemiacetal can or lactol can always be converted to ______.

A

Acetal

51
Q

What reagent is needed for the hydrolysis of imines in acidic media? 

A

H2O/H+

Produces a ketone and a primary amine

52
Q

What region is needed for the hydrolysis of enamines in acidic media?

A

H2O/H+

53
Q

Alpha-D-glucose (hemiacetal) is ….

Beta-D-glucose (hemiacetal) is…..

A

Axial

Equatorial (major product)

54
Q

Is sugar that has an aldehyde, a ketone, a hemiacetal, or a hemiketal is called a…

A

Reducing sugar. These can reduce an oxidizing agent such as Br2

55
Q

What are some bon-reducing sugars?

A

Acetals, Ketals, alpha and beta glycosides

56
Q

What test is used for aldehydes only? What kind of reaction is it?

A

The Tollen’s silver mirror test

Oxidation reaction

57
Q

Tollens reagent is prepared by dissolving…..

A

Silver oxide in ammonia. Reacts with aldehyde to give a silver mirror 

58
Q

what does the Fehlings test for?

A

For aldehydes.

Oxidizes aldehyde to a carboxylic acid

59
Q

How is Fehling’s test prepared? 

A

Cu2+ -tartare complex in alkaline solution

Cu+ Combines with oxygen to give a Cu2O brick red precipitate. 

60
Q

What is another test for aldehydes that is similar to Fehlings reagent? What does it use instead? 

A

Benedicts test for aldehydes

Citric acid instead of Tartaric acid

61
Q

What kind of reaction is the bisulfate test?

What does it test for?

A

-An addition reaction
-aldehydes and ketones


62
Q

Test where a small amount of 20% aqueous sodium bisulfite solution is added to an aldehyde or ketone
-A positive test produces white bisulfate compound crystals

A

Bisulfite Test

63
Q

The Shiff’s Fuchsin-aldehyde test?
Is for what only?
What type of reaction is it?

A

Aldehydes

Complex addition reaction

64
Q

And this test a Faintly pink dye is decolorized by sulfur dioxide this reagent turns purple in the presence of an aldehyde

A

The Schiff’s Fushin-Aldehyde Test

65
Q

Treatment of an aldehyde or ketone with either _____ or ______ followed by protonation of Forms a Primary or secondary alcohol*

A

NaBH4, LiAlH4

Ochem 2 (10 decks)

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