Chapter 18

Question 1

Aldehydes and ketones contain substituents that cannot stabilize a _______ charge (ex C and H):
1) these are _______ leaving groups
2) no acyl _______ reactions

Answer 1

negative
1) poor
2) substitution

Question 2

the C=O bond is _______, _______, and _______ compared to the C=C bond

Answer 2

shorter
stronger
polarized

Question 3

What is the IUPAC ending for aldehydes

Answer 3

-al

Question 4

What is the IUPAC ending for ketones

Answer 4

-one

Question 5

Common aldehydes and ketones (for C=O compounds: 1C = _______; 2C = _______)

Answer 5

Form
Acet

Question 6

IUPAC Ketones:
1) number the chain so that the C=O has the _______ number
2) Replace the alkane -e with _______
3) In cyclic ketones, the carbon is assigned number ____
4) if deciding between the C=O and C=C, _______ wins

Answer 6

1) lowest
2) -one
3) 1
4) carbonyl

Question 7

IUPAC Aldehydes:
1) the aldehyde carbon is always number ____
2) replace the alkane -e with _______
3) if CHO is attached to a ring, the suffix _______ is used

Answer 7

1) 1
2) -al
3) carbaldehyde (carboxaldehyde)
- in this case there are “2 roots”

Question 8

carbonyl as a substituent: on a molecule with a higher priority functional group, a ketone is an _______ and an aldehyde is a _______

Answer 8

oxo
formyl

Question 9

Boiling points:
1) Ketones and aldehydes are more _______, so they have a _______ boiling point than comparable alkanes or ethers
2) they cannot hydrogen bond to each other, so their boiling point is _______ than comparable alcohols

Answer 9

1) polar; higher
2) lower
Alkanes<ethers<aldehydes<ketones<alcohols

Question 10

solubility of ketones and aldehydes:
- they are good solvents for _______. Lone pairs of the electrons on the oxygen of the C=O can accept a hydrogen bond from OH or NH. miscible in water

Answer 10

alcohols

Question 11

What reagents are needed to turn carboxylic acid into a ketone?

Answer 11

1) 2 eq RLi, ether
2) H3O+
- 1 eq of grignard deprotonates

Question 12

What reagents are needed to turn nitriles into ketones?

Answer 12

1) Grignard (PhMgBr), ether
2) H3O+
- PADPAD

Question 13

What reagents are needed to turn nitriles into aldehydes?

Answer 13

1) DIBAL-H
or (i-Bu)2Al-H
2) H3O+

Question 14

What reagents are needed to turn Carboxylic acids into acid chlorides and aldehydes?

Answer 14

1) SOCl2
2) LiAlH(OtBu)3

Question 15

What reagents are needed to turn Carboxylic acids into acid chlorides and ketones?

Answer 15

1) SOCl2
2) R2CuLi (Gilman)

Question 16

What reagents are needed to turn esters into aldehydes?

Answer 16

1) DIBAL-H
2) H2O

Question 17

What are the steps to nucleophilic addition (basic)

Answer 17

1) attack
2) protonate
- no strong acid allowed and good Nuc- needed

Question 18

What are the steps to nucleophilic addition (acidic)

Answer 18

1) protonate
2) attack
3) deprotonate
- needs strong acid and weak Nuc: used

Question 19

What are the 2 factors that effect the reaction rates of aldehydes and ketones in nucleophilic addition?

Answer 19

1) steric
2) electronic (inductive)

• δ+ needs to be attacked so open and unstable = more reactive [small groups and EWG :) ]

Question 20

rates of aldehydes and ketones in nucleophilic addition:
The larger the R-groups on the C=O, the _______ the reaction

Answer 20

slower

Question 21

rates of aldehydes and ketones in nucleophilic addition:
- EWG = _______
- EDG = _______

Answer 21

EWG = destablized δ+ = more reactive
EDG = stablized δ+ = less reactive

Question 22

aldehydes and ketones react with water to give _______ diols

Answer 22

geminal

Question 23

The addition of water to aldehydes and ketones is an equilibrium reaction that is _______, and nucleophile attack of H2O can be catalyzed by basic and acidic conditions

Answer 23

reversible
- favoring carbonyl (reactant) compounds

Question 24

Aldehydes and unhindered ketones react with HCN to give _______

Answer 24

cyanohydrin

Question 25

Aldehydes and unhindered ketones react with HCN to give cyanohydrin, which works best under slightly _______ conditions

Answer 25

basic - will favor **tetrahedral** product in most cases unless extended conjugation (phenyl)

Question 26

Addition of HCN to acetophenone is less reactive than acetone because: 1) product has higher energy compared to starting acetophenone because it is less _______ 2) the benzene ring introduces _______

Answer 26

1) conjugated 2) sterics - both because of the benzene ring

Question 27

adding an EDG to phenyl on acetophenone will result in a _______ reaction

Answer 27

slower - stabilizes carbonyl (making it less electrophilic) (less attackable)

Question 28

Formation of imine (C=N-R) occurs under slightly _______ conditions

Answer 28

acidic - PAD PAD

Question 29

What is another name for imines?

Answer 29

Schiff base - have to contain an R group though

Question 30

What is the name for the most stable intermediate in the mechanism for formation of imines?

Answer 30

carbinol amine aka hemiaminal

Question 31

What's the difference in mechanism for the formation of imines if there is a 2° amine instead of a 1° amine? What is the name of the molecule it forms?

Answer 31

at the end of 2° amine addition, the 2nd hydrogen is taken 1 away from the carbon attached to the Nitrogen - forms **enamine** (nitrogen on a double bond)

Question 32

Imine products should always be drawn _____

Answer 32

(E)

Question 33

imines are nitrogen analogues of ketones and aldehydes with a _____ bond in place of the carbonyl group

Answer 33

C=N

Question 34

make sure to learn names of other condensations with amines

Answer 34

https://quizlet.com/1021257036/other-condensations-with-amines-diagram/?i=1ha23w&x=1jqt

Question 35

Synthesis of acetals is _______ and equilibrium often favors the _______

Answer 35

reversible reactants - remove water (lechatelier's) to drive rxn forward

Question 36

What are the steps (ex PAD) for formation of acetals?

Answer 36

PADPA**A**D

Question 37

What is the nucleophile for hydrolysis of acetals?

Answer 37

H2O Reagents: H3O+ **useful in synthesis**

Question 38

Formation of acetals requires slightly _______ conditions

Answer 38

acidic

Question 39

hemiacetals are not favored at equilibrium even though they are super stable. The only exception found in nature is a _______ hemiacetal

Answer 39

cyclic hemiacetal

Question 40

Often a _______ is used in the preparation of acetals. the reaction is more favorable because the conversion of a hemiacetal ------> acetal is reversible

Answer 40

diol - intramolecular **tethered** system, so it is faster than any competing nucleophile

Question 41

aldehydes form acetals _______ than ketones, allowing for selective protection of different carbonyl functional groups

Answer 41

more

Question 42

The Wittig reaction converts a _______ into a new _______

Answer 42

C=O C=C - this is why it won a nobel in 1979

Question 43

The Wittig reaction requires a _______ that is used as the nucleophile in the reaction

Answer 43

phosphorus ylide

Question 44

Phosphorus ylide is prepared from triphenylphosphine and an unhindered alkyl halide = _______, butyl lithium is then used to abstract a hydrogen from the carbon attached to the phosphorus to form the ylide

Answer 44

Sn2

Question 45

In general, the ylide should come from an _______ alkyl halide (ensures fast reaction)

Answer 45

unhindered - cuz Sn2

Question 46

Wittig reaction products should always be drawn _____

Answer 46

(Z) - cis

Question 47

_______ test involves adding a solution of **silver**-ammonia complex to the unknown compound to test for _______

Answer 47

Tollen's aldehydes

Question 48

What is the best reagent to use for oxidation of aldehydes?

Answer 48

Ag2O - oxidizes only aldehyde not DB

Question 49

What are the two ways to deoxygenate a ketone or aldehyde?

Answer 49

1) Clemmensen reduction 2) Wolff-Kishner reduction - takes of C=O

Question 50

What are the reagents for Clemmensen reduction?

Answer 50

Zn(Hg), HCl, H2O

Question 51

What are the reagents for Wolff-Kishner reduction?

Answer 51

1) NH2NH2 (hydrazine), pH~4.5 2) KOH, Δ - step 2 is true WF red, wf red works on imines and oximes formed by step 1

Question 52

In what scenarios would Clemmensen be used over Wolff-Kishner reduction?

Answer 52

1) When you start with a Carboxylic acid 2) Get rid of acetal 3) Turn nitro into amine

Question 52

In what scenarios would Wolff-Kishner reduction be used over Clemmensen?

Answer 52

1) When you have amides in OG compound 2) keep acetal 3) keep nitro