Ch 16 - Aldehydes and Ketones

the C=O groups is known as

a carbonyl group

aldehydes nomenclature

-al suffix (no positional number required)

ketones nomenclature

-one suffix (position must be indicated)

the carbonyl group is

highly polar

high polarity results in

a higher boiling point than alkanes or ethers, but lower than alcohols or carboxylic acids (H-bonding)

the carbonyl group is a

hydrogen bond acceptor

carbonyls solubility

• water soluble if low molecular weight

• less soluble than alcohols or carboxylic acids

PCC reagent

turns alcohol to aldehyde

H2CrO4 reagent (or PCC)

turns alcohol into ketone

alkene to ketone

hydration reaction: HgSO4, H3SO4, and H2O

alkene to aldehyde (hydroboration reaction_

1. BH3

2. NaOH, H2O2

the polarity of the carbonyl group results in the carbon having

a partial positive charge

the carbonyl carbon is electrophilic; nucleophiles will add

to give alcohol products

weak nucleophiles (ROH_ usually require a

acid catalyst to react with carbonyls

aldehydes and ketones are

achiral

if the substituents on the carbonyl carbon are different, addition of a nucleophile will create

a chiral center

RLi and RMgX will add to aldehydes or ketones to

give alcohol products

gilman reagents (R2CuLi) do not react with

carbonyls

witting reaction converts

an aldehyde or ketone to an alkene using a phosphorus ylide

unlike carbanions, addition of weak nucleophiles is generally

a reversible equilibrium

water reacts with aldehyde and ketones to give a

hydrate

alcohol react with aldehydes and ketones to give

hemiacetals (catalyzed by acid or base)

imine =

double bond

amine =

single bond

1. Ag2O, NaOH

2. HCl

aldehyde to carboxylic acid

1. Ag2O, NaOH

2. HCl

   1. vs H2CrO4

same effect (aldehyde to carboxylic acid)

Pinnick oxidation

NaH2PO4 and alkene

pinnick oxidation effect

aldehyde to carboxylic acid alcohol halide

aldehydes and ketones can be reduced to alcohols by reacting a

hydride (H-) reagent

reduction of carbonyls to alcohols common reactants

NaBH4 and LiAlH4

reduction with LiAlH4 and H3O+

ketone to alcohol

amines can be made by reacting

an aldehyde or ketone or amine in the presence of a reducing agent

reductive maintain - imine reduction

an immune forms, followed by reduction to an amine

NaBH3CN , CH3OH

ketone to amine (+ addition chain)

clemmensen reduction

Zn(Hg), HCl

clemmensen reduction reaction

ketone to alkane

wolff-kishner reduction

H2NNH2, KOH and H2O

H2NNH2, KOH and H2O

aldehyde to alkane

tautomerization

rapid equilibrium due to movement of an atom or groups of atoms - usually movement of a proton

a-bromination

Br2 and acid

a-brominatin reaction

aldehyde with addition of Br