Ch. 17 - Aldehydes And Ketones: Nucleophilic Addition To Carbonyl Groups

Front 1

List 10 reactions from Ch. 17 involving Aldehydes and/or Ketones

Back 1

- Acid Catalyzed Hydration (of Aldehydes and Ketones)
- Base Catalyzed Hydration (of Aldehydes and Ketones)
- Cyanohydrin Formation
- Acetal Formation
- Primary Amines
- Secondary Amines
- Wittig Reaction
- Oxidation of Aldehydes
- Tollen's Test
- Baeyer-Villiger Reaction

Front 2

PROPERTIES/REAGENTS/STEPS/PRODUCTS OF:

Acid-Catalyzed Hydration of Aldehydes and Ketones

Back 2

- Reversible reaction

Reagents:
1. H2O
2. Acid (H3O+, HCL, etc)

Step 1: Acid protonates carbonyl oxygen (making carbonyl C more electrophilic)

Step 2: Water attacks carbonyl carbon. Electron pair of the double bond is pushed on to the carbonyl oxygen

Step: Another H2O molecule takes a proton from the bonded H2O molecule

Product: Geminal Diol

Front 3

REAGENTS/STEPS OF:

Base-Catalyzed Hydration of Aldehydes and Ketones

Back 3

Reagents:
1. Hydroxide salt
2. Water

Step 1: -OH attacks carbonyl carbon. Electron pair of the double bond is pushed on to the carbonyl oxygen

Step 2: H2O protonates the carbonyl oxygen

Front 4

PROPERTIES/REAGENTS/PRODUCT OF:

Cyanohydrin Formation

Back 4

Reversible reaction (using a base)

Reagents: HCN (aq)
-can also use NaCN + H2O, then add acid

Product: Cyanohydrin + H2O

Front 5

List the steps for Acetal Formation

Back 5

Step 1: Aldehyde or Ketone transformed into hemiacetal. (carbonyl oxygen is protonated, carbonyl carbon gets ether group)

Step 2: Acid protonates the alcohol, subsequent H2O dissociates

Step: 2nd Equivalent of alcohol attacks carbocation

Step: 3rd equivalent abstracts proton from newly attached alcohol

Product: Acetal

Front 6

Describe the structure of an Acetal

Back 6

Carbon with 2 (geminal) ethers attached

Front 7

Describe the structure of an Hemiacetal

Back 7

Carbon with an alcohol and ether group attached geminally

(alcohol is from protonation of carbonyl O)

Front 8

REAGENTS FOR:

Acetal Formation

Back 8

1. 2 eq. alcohol (or excess)
2. Acid (H3O+ or HCl)

Front 9

Basic Steps for using Acetals as protecting groups.

Back 9

Step 1: Turn Carbonyl groups to Acetals for protecting

Step 2: Carry out reactions that are incompatible with group being protected

Step 3: Once finished, de-protect via Acetal Hydrolysis

Front 10

STEPS/PRODUCTS OF:

Aldehyde or Ketone reaction with Primary Amines

Back 10

Step 1: Aldehyde or Ketone is attacked by the nitrogen of R-NH2

Step 2: Oxygen is protonated, and NH2 is deprotonated, giving carbinolamine

Step 3: OH group is protonated for second time to give -OH2 group

Step 4: -OH2 group dissociates and N lone pair is pushed into double bond with C

Step 5: + charge on N allows for its proton to be removed.

Product:
1. Imine
2. H2O

Front 11

REAGENTS/STEPS OF:

Aldehyde or Ketone reaction with Primary Amines

Back 11

Reagents: Benzene, heat

Step 1: Proton attached to N protonates carbonyl oxygen.

Step 2: Nitrogen attacks the carbonyl carbon, forming carbinolamine.

Step 3: Lone pair on N pushed to form double bond with C and the -OH group dissociation

Step 4: A beta proton is pulled off forming C-C double bond, and a pair of electrons from C-N double bond are pushed back to the N

Front 12

Describe an "imine"

Back 12

Imine has a N double bonded to C

Front 13

Describe an "enamine"

Back 13

"ene" + "amine"

carbonyl carbon gets a NR2 group and a C-C double bond

Front 14

The main product of Wittig reaction is..

Back 14

Alkenes

Front 15

SUBSTRATES/PROPERTIES/SOLVENT OF:

Wittig reaction

Back 15

Substrates involved: Ketone/Aldehyde, triphenyl phosphonium ylide

Replaces C=O of ketone/aldehyde with C-R' of (C6H5)3-P-R'

Solvents: THF or DMSO

Front 16

REAGENTS/PRODUCTS OF:

Oxidation of Aldehydes

Back 16

Reagents: K2Cr2O7, H2SO4, H2O

Products: Carboxylic acid

Front 17

PROPERTIES/REAGENTS OF:

Tollen's Test

Back 17

Reaction of Aldehyde with Ag+ (AgNO3) to replace aldehyde hydrogen with O-+NH4.

If aldehyde, Ag+ will be reduced to Ag and precipitate to form mirror

Reagents: NH3, H2O

Front 18

PROPERTIES OF:

Baeyer-Villiger Reaction

Back 18

Reaction of a peroxyacid and a ketone to give an ester and a carboxylic acid

- Retention of stereochemistry
- Oxygen from peroxyacid inserts between carbonyl C and its more substituted R group.