Chapter 20 and 21 Orgo II

ester nomenclature

ester nomenclature

Esters are named as alkyl alkanoates. The alkyl group connected to the oxygen is named first, followed by the group attached to the carbonyl.

The acyl portion is named by substituting the suffix -ate

Amide nomenclature

When naming amides, replace the -ic acid or -oic acid of the corresponding carboxylic acid with -amide.  Substituents, irrespective of whether they are attached to the acyl group or the amide nitrogen, are listed in alphabetical order. Substitution on nitrogen is indicated by the locant N-.

nitriles

substitutive IUPAC names for nitriles add the suffix -nitrile to the name of the parent hydrocarbon chain that includes the carbon of the cyano group

less stable to most stable

acyl chlorides, acid anhydrides , esters, amides

acyl chlorides to carboxylic acids

acyl chlorides to acid anhydrides

acyl chlorides to esters

acyl chlorides to amides

acid anhydrides to esters

acid anhydrides to amides

carboxylic acid to ester

Baeyer-Villiger oxidation of ketones

oxygen goes to the more substituted side

esters to amides

hydrolysis of esters

acid catalyzed hydrolysis of esters

saponification

RETENTION OF CONFIGURATION

Reaction of Esters with Grignard and Organolithium Reagents and Lithium Aluminum Hydride

Amide Hydrolysis

Formation of (+) tetrahedral intermediate and then disassociation of NH3

Amide Hydrolysis in Basic Solution

products are carboxylate and ammonia

Nucleophilic substitution by cyanide ion

Cyanohydrin formation

Nitrile Hydrolysis in Basic Solution

nitriles to ketones

Write the structure for this name

Write the structure for this name

What does this yield?

Mechanism of reaction between esters and amines

Claisen Condensation

ethyl phenylacetate

retrosynthesis of this compound

write the mechanism

diethyl malonate

make 2-Bromo-3-pentanone from 3-pentanone

make 1-Penten-3-one from 3-pentanone

make 3-Hexanone from 3-pentanone

make 2-Methyl-l-phenyl-l-penten-3-one from 3-pentanone

2-Allyl-1,3-propanediol from propene

3-Phenylpropanoic acid from benzyl bromide

and use PCC to make the alcohol to a aldehyde

Make the alcohol to an aldehyde. Diels Alder is last

Outline a reasonable mechanism

Outline a reasonable mechanism

First add the hydroxide, then reinstate the carbonyl by taking a hydrogen from water. Then the rest is the photo

Outline a reasonable mechanism

Enol

acid catalyzed

Enolate

Aldol condensation mechanism

aldol condensation trick

replace the alpha hydrogen with the double bond of the electrophilic carbonyl

state the product

a strong base used to create enolates

LDA

Claisen Condensation

one ester is the source of both the acyl group and the enolate and the product is a β-keto ester (must have at least 2 alpha hydrogens)

Claisen Condensation Mechanism

Alkylation of enolates

Simple aldehyde, ketone, and ester enolates are relatively basic, and their alkylation is limited to methyl and primary alkyl halides

Alkylation of bicarbonyls, hydrolysis and decarboxylation

Methyl, primary, and unhindered secondary alkyl halides are satisfactory alkylating agents. Elimination (E2) is the only reaction with tertiary alkyl halides

Acid catalyzed enolization mechanism

Halogenation of aldehydes and ketones

X2 and an acid (ie acetic acid)

Haloform reaction

Methyl ketones undergo a novel C–C cleavage on treatment with excess halogen in the presence of base.

Haloform Reaction Mechanism

Substitution of deuterium for hydrogen at the α-carbon atom of an aldehyde or a ketone is a convenient way to introduce an isotopic label into a molecule and is readily carried out by treating the carbonyl compound with deuterium oxide (D2O) and base

Which is more stable?

α,β-unsaturated aldehydes and ketones are more stable than their nonconjugated isomers

What is the product?

The Michael reaction is an alkylation in which unsaturated ketone serves the same kind of electrophilic role that alkyl halides do toward the enolate.

lithium dialkylcuprates and alpha-beta conjugated ketones

The beta carbon of an alpha, beta unsaturated carbonyl compound is electrophilic;

The nucleophile bonds to the beta carbon