Alpha

Question 1

Reasons for Aldehyde > Ketone in reactivity

Answer 1

1. Polarization (Less R)
2. Steric Hindrance -> The H on the aldehyde is much smaller than an R group therefore does not have as much steric hindrance

Question 2

Function of Halogen to Ketone and Aldehydes

Answer 2

The make it more reactive or any other electronegative element because they make it much more electropositive for nucleophilic attack and like

Question 3

Diol + Ketone/Aldehyde

Answer 3

Protection of the carbonyl and prevent attack

Question 4

Function of Thioacetal

Answer 4

1. Act as protective groups.

2. By Raney Ni: Thet add H to the C and reduce it specfically

Question 5

Raney Reagent Function

Answer 5

Specifically reduces the Thioacetal by adding Hydrogens

Question 6

Imines and Enamines Functional group

Answer 6

Imines - C=N-Y, where Y - H or R
Enamines: C-N-R2, where the next C is made a double bond, detachment of the H is done by a base (base which is the functional group N)

Question 7

Iminium Ion

Answer 7

C=N-Y-H or R with +ve charge

Question 8

Oximes

Answer 8

C=N-Y where Y = OH

Question 9

Hydrazone

Answer 9

C=N-Y, where Y - NHR or NH2

Question 10

NaBH4 specific addition pattern to aldehyde and ketone

Answer 10

Hydride adds directly to the Carbon (reduces the carbon)

Question 11

Why is LiAlH4 used dry as a reducing agent?

Answer 11

When wet, it can form H2 gas which can be dangerous. It is much more electropositive than NaBH4, hence, it donates hydrides much more easily

Question 12

Functional Difference between NaBH4 and LiAlH4

Answer 12

NaBH4 cannot reduce carboxylic acids

LiAlH4 reduces carboxylic acids

Question 13

Difference between specific reactants acted on

Answer 13

NaBH4 reduces ketones and aldehydes

LiAlH4 reduces esters, carboxylic acids all to aldehydes all the way to alcohols.

Question 14

Tollen’s Reagent vs. Jones Reagent (na2Cr2O7)

Answer 14

Tollen’s Reagent selectively oxidizes aldehydes and maybe ketones

Jones Reagent oxidizes everything: ketones, alcohols, aldehydes

Question 15

Change in Cr Oxidation number when oxidizing?

Answer 15

Cr6+ goes to Cr3+

Question 16

PCC vs Jones Reagent

Answer 16

PCC oxidizes only one step that is: alcohol to aldehyde

Jones reagent goes straight to ester or carboxylic acid

Question 17

PCC vs Tollen’s reagent

Answer 17

PCC only takes it up one step in terms of alcohol to aldehydes

Tollen’s reagent only attacks aldehydes and ketones and takes it to the end

Question 18

TBDMSCl function

Answer 18

Protects Alcohol like thioacetals and diols protect ketones/aldehydes

Question 19

Tosylates and Mesylates chemical form

Answer 19

Tosylates - TsCl

Mesylates - MsCl

Question 20

Tosylates and Mesylates Function

Answer 20

They both make alcohols a better leaving group

Question 21

Tosylates and Mesylates vs. TBDMSCl

Answer 21

Tosylates and Mesylates function to make it a better leaving group the alcohol for nucleophilic attack

TBDMSCl protects it like diols and thioacetals

Question 22

4 Criteria of Aromaticity

Answer 22

1. Cyclic
2. Planar
3. Conjugate
4. Huckel’s Rule: 4n + 2 = pi electrons

Question 23

What is the technique of Benzene and Pyridines to know if something follows Huckel’s Rule?

Answer 23

Always make sure that you have checked all resonance structures to be sure that it is showing the most amount of double bonds. Use Benzene as a model

Question 24

BH3, THF function

Answer 24

Reduces by one step down by only converting a carboxylic acid down to a ketone or aldehyde but will not take it to the alcohol

Question 25

BH3, THF vs NaBH4

Answer 25

BH3, THF takes only one step down: Will react with both carboxylic acids and maybe ketone or aldehyde but takes it one step down NaBH4 cannot react with carboxylic acids that is why it needs LiAlH4. It only breaks down aldehydes or Ketones but cannot attack carboxylic acids

Question 26

BH3, THF vs LiAlH4

Answer 26

BH3, THF takes carboxylic acids down one step LiAlH4 rakes it all the way to an alcohol

Question 27

What does SoCl2 attack in the formation of acid chlorides from Carboxylic acids

Answer 27

O from the C=O binds to the S and the Cl leaves. Cl attacks the C after other reactions and the O an SOCl leave because water has been formed in one case and things are balanced.

Question 28

Function of DCC

Answer 28

Carboxylic acid plus ammonia can give amides but a much more better way is to use DCC with Nitro groups and carboxylic acids

Question 29

Beta-Lactam

Answer 29

Amide in a Ring

Question 30

Biological function of DCC, carboxylic acid and an amino group

Answer 30

Formation of peptide bond. To form this from two amino acids, for the left amino acid, protect its amino group, and for the right amino acid, protect its carboxylic group and then use DCC to form the peptide bond between carboxylic acid and amino group

Question 31

Amide Functional group

Answer 31

O=C-N

Question 32

Amide vs Imine

Answer 32

Amide - O=C-N Imine: C=N-Y