Everything

Question 1

Reduction of ketone/aldehyde via NaBH4

Hydride donor

Answer 1

• selective reduction of ketones or aldehydes
• racemic

Question 2

Reduction of ketone/aldehyde via LiAlH4

Hydride donor

Answer 2

• selective reduction of ketones or aldehydes
• racemic

Question 3

Reduction of ester via LiAlH4

Hydride donor

Answer 3

• will reduce carboxylic acid or ester
• racemic

Question 4

Reaction of Grignard reagent and ketone/aldehyde

Answer 4

• carbon withdraws electron density from magnesium via induction
• Have to reduce all the way to acid. **cannot stop at intermediate
• **will not react with carboxylic acid

Question 5

Reaction of Grignard reagent and ester

Answer 5

• carbon withdraws electron density from magnesium via induction
• Have to reduce all the way to acid. **cannot stop at intermediate
• **will not react with carboxylic acids

Question 6

Which mechanism will not selectively reduce carbonyls in the presence of a C=C?

Answer 6

Catalytic Hydrogenation

Question 7

How do you protect an alcohol?

Answer 7

1. Protect hydroxyl group with protecting group (aprotic)
2. Form the Grignard reagent
3. Remove the protecting group

Question 8

Mechanism

Oxidation of an alcohol with chromic acid

Oxidation of alchohol

Answer 8

• Primary alchohol yields carboxylic acid (hard to stop at aldehyde)

Question 9

Mechanism

Swern Oxidation

Oxidation alchohols

Answer 9

• First (aldehyde) and second (ketone) degree alchohols
• Low temp (often -78C)

Question 10

SN2

Answer 10

• Inversion of configuration (back-side attack)
• Second order
• Sensitive to number of substituents at alpha position (steric hindrance)
• Strong nucleophile
• Does not occur at sp2 hybridized center

Question 11

Halogenation

Answer 11

Question 12

Halohydrin Formation

Answer 12

Question 13

Mechanism

Williamson Ether Synthesis

Answer 13

Question 14

Mechanims

Williamson Ether Synthesis 2

Answer 14

Question 15

Sharpless Epoxidation

Enantioselective epoxidation

Answer 15

• requires allylic alcohol
• reagents = Ti[OCH(CH3)2]4 and =/- DET

Question 16

Oxidation of Thiol

Answer 16

Question 17

Preparation of Sulfides from Thiols

Answer 17

Question 18

How do you determine the relative stability of anionic conjugate bases?

Answer 18

• A- the atom bearing the charge
• R- resonance
• I- induction
• O- orbitals

Question 19

How does an atom affect the stability of an anionic charge?

Answer 19

1. Electronegativity increases as you go to the right across the rows
2. Atom size increases as you move down a column, allowing for a larger volume of space to stabilize the charge

Question 20

Mechanism

Reaction between SOCl2 and an alcohol

Answer 20

• SN2
• Primary or secondary alcohols

Question 21

Reaction between PBr3 and an alcohol

Answer 21

• SN2
• Primary and secondary alcohols

Question 22

Mechanism

Hydroboration Oxidation

Answer 22

• Anti-Markovnikov
• Syn-addition

Question 23

Mechanism

Acid-Catalyzed Hydration

Answer 23

• Markovnikov
• carbocation rearrangment
• Dilute acid

Question 24

What are the classes of dienes?

Answer 24

Question 25

What is a Diels-Alder reaction?

Answer 25

Question 26

Electrocyclic reactions

Answer 26