CH5: Alcohols from Carbonyl Compounds: Oxidation-Reduction and Organometallic Compounds

Question 1

Types of carbonyl groups

Answer 1

1) C.A.
2) Ester
3) Aldehyde
4) Ketone

Question 2

C.A. reduction

Answer 2

Reduce to a primary alcohol

Need LAH in ether soln followed by H2O and acid

Question 3

LAH

Answer 3

Strong reducing, reduces everything

Needs -78 to 0 degrees

Question 4

NaBH4

Answer 4

Weak reducing, only ketones and aldehydes

Question 5

Ester reduction

Answer 5

Reduced to a primary alcohol

1) LAH, Ether
2) H2O, H2SO4

OR

1) High pressure, heat, and H source (hydrogenation at a high pressure)

Question 6

Aldehyde + Ketone reduction

Answer 6

Primary alcohol and secondary alcohol

Reduced with LAH or NABH4, NaOH

Question 7

What do reducing agents do

Answer 7

Provide a hydride source (H-) to act as a nucleophile on a pi bond

Question 8

Primary alcohol oxidation

Answer 8

KMnO4 can oxidize all the way to C.A. it is strong

Use PCC to stop at the aldehyde stage

Question 9

KMnO4

Answer 9

Strong oxidizing agent takes primary alcohols to C.A.

1) KMnO4, OH-/H2O 2) H3O+

Question 10

PCC

Answer 10

Stops oxidation of primary alcohols at the aldehyde stage, it is used in organic solvents ex. CH2Cl2 and heat

Question 11

Ketone oxidation

Answer 11

1) Chromic acid: H2CrO4 in acetone with heat
OR
2) Jones reagent: CrO3 in acetone with heat

Question 12

Chromic acid/Jones regant

Answer 12

Form ketones from secondary alcohols

Question 13

Aldehydes in water form________

Answer 13

Hydrates, if we use H2CrO4 after it can then be attacked to form a D.B.

Question 14

A bond is ______reactive the more ionic it is

Answer 14

More

Question 15

Organometallic compounds

Answer 15

C-Metal bonds hence organo (carbon) metallic (metal), can turn carbon into a nucleophile instead of an electrohile because the metal is super positive

Question 16

Organolithium reagants

Answer 16

React an alkyl halide with 2Li in ether solution
R-Li and Li-X form

Reactivity-Use I or Br only

Question 17

Gringard reagents

Answer 17

Mg and an alkyl halide in ether solution produces this

Question 18

What is important when dealing with organolithium + grignard reagents

Answer 18

They are super basic and will remove an H from alcohols, water, any H attached to N, O or S.

They must be used in anhydrous (no hydrogen soln)

Question 19

Alkynides

Answer 19

Organometallic reagants are great for creating a CT.B.N nucleophile. These compounds are great nucleophile and can add carbon-carbon bonds

Question 20

Grignard + oxiranes (epoxides)

Answer 20

This leads to ring opening at the least substituted carbon and forms a C-C bond 2 carbons down from the alcohol’s hydroxyl group. H3O+ is used at the end

Question 21

Primary alcohol from grignard and ketone/aldehyde

Answer 21

The grignard attacks the carbon forming an alkoxide. This is then protonated by acid, yielding a 1, 2, or 3 alcohol

Question 22

Formaldehyde + Grig
Aldehyde + Grig
Ketone + Grig

Answer 22

1, 2, 3 ALCOHOLS…always bumps up one because r group is added to the carbonyl carbon

Question 23

Sodium alkynides (NaNH2)

Answer 23

Create nucleophiles, especially for C tb C with an acidic H

Question 24

Tertiary alcohol from ester

Answer 24

2 moles of grignard reagent followed by NH4Cl/H2O yields a tert alcohol

-OR is the first L.G.