carboxylic acids and carboxylic acid derivatives

induction

having an electron withdrawing group. stabilizes a base.

carboxylic acid

R-COOH. good electrophile due to dipole. always a terminal group

carbonyl

C=O

alcohol

R-OH

ester

RCOOR

typically found as the product of a condensation reaction with an alcohol and and acid.

nitrile

RCN

nucleophilic addition

addition reaction where a chemical compound with an electron-deficient or electrophilic double or triple bond (pi bond) reacts with electron rich reactant (nucleophile). double or triple bond disappears and creates two new single bonds

amide

NH2

fisher esterification

formation of ester from carboxylic acid and an alcohol initiated by an acid catalyst

acid catalyst protonates the alcohol --> forms oxonium ion --> protonates carboxylic acid --> carboxylic acid open to nucleophilic attack by the alcohol --> water eliminated yields protonated ester

acid anhydride

an oxide that forms an acid when reacted with water

primary alcohols

only one carbon attached to the carbon with the hydroxyl functional group. can be oxidized to a ketone

decarboxylation

The complete loss of a carboxyl group as carbon dioxide

halogenation

The substitution of Hydrogen with one or more Halogens (Group VIIA elements).

nucleophile

An electron pair donor

electrophile

An electron pair acceptor

carboxylic acid nomenclature

-oic acid

carboxylate

deprotonated carboxylic acid. very stable. bases can deprotonate carboxylic acids

carboxylate nomenclature

-ate

acid proton is relatively acidic due to carboxylate stability. adding electron withdrawing groups to the the acid increases the acidity of the carboxylic acid. acidity increases with the number and proximity of the EWG

carboxylic acid acidity

nucleophilic acyl substitution

The substitution of a nucleophile for the leaving group of a carboxylic acid or carboxylic acid derivative.

amide condensation

carboxylic acid to amide. amine (NH2-R) attacks carbonyl of carboxylic acid

esterification

carboxylic acid to ester. carboxyl is attacked by an alcohol. reaction is often catalyzed by an acid

ester nomenclature

-oate

ketone

R-C=O-R. common electrophiles

oxidation

loss of electrons

reduction

gain of electrons

induces oxidation of primary alcohols and aldehydes to carboxylic acids, secondary alcohols to ketones

strong oxidizing agent reactions

Hot KMnO4

Na2Cr2O7

Jones reagent

H2CrO4

strong oxidizing agents

CrO3, H2SO4, and acetone

jones reagent

primary alcohol to aldehydes

secondary alcohols to ketone

weak oxidizing agent reactions

PCC

weak oxidizing agent. alcohols to aldehydes

PCC components

CrO3 and pyridine

carboxylic acids to primary alcohols

ketones to secondary alcohols

esters to alcohols

amides to amines

strong reducing agent reactions

LiAH4

strong reducing agent

aldehydes to primary alcohols

ketones to alcohols

weak reducing agent reactions

NaBH4

weak reducing agent

need oxidant

disulfide bond formation

need reductant. reactants like B-mercaptoethanol or dithiolthreiol (DTT) use their own sulfurs to create their own disulfide bonds

disulfide bond breaking

haworth projection

A method for depicting cyclic sugars as planar rings with -OH groups sticking up or down from the plane of the sugar

aldose

monosaccharide characterized by the presence of an aldehyde functional group

ketose

monosaccharide characterized by the presence of a ketone

cyclization of sugars

aldehyde to hemiacetal or ketone to hemiketal. anomeric carbon is a new chiral center

hemiacetal in sugars

when the O on carbon 5 attack the C1 carbon to create a ring. the C1 carbon becomes the anomeric carbon

hemiketal in sugars

when the O on carbon 5 attacks the C2 carbon to create a ring. the C2 carbon becomes the anomeric carbon

sucrose

won't yield a positive on Tollen's test

mutarotation

The rapid interconversion between different anomers of a sugar

beta-anomer

the OH group of the C1 cis to the CH2OH group

it will be equatorial and up

alpha-anomer

OH group in the C1 is trans to the CH2OH

it will be axial and down

tollen's reagent

uses silver nitrate as an oxidizing agent;

positive test results in aldehydes reducing Ag+ to metallic silver

Benedict's solution

A chemical indicator that, when added to a solution and heated, changes from blue to light green to red in the presence of increasing concentrations of sugar.

fehling's test

Aldehyde can reduce Cu2+ to Cu+

reducing sugars

Sugars that produce a red precipitate when boiled with Benedict's solution. aldoses or terminal alpha-hydroxy ketones. E.g. glucose, maltose, fructose, lactose.

tautomerization

the rearrangement of bonds in a compound, usually by moving a hydrogen and forming a double bond

partial positive or positive charge makes a good

electrophile

partial negative or full negative charge makes a good

nucleophile

amine

NH2

imine

A double bond between a carbon and a nitrogen

SN1 reaction

*unimolecular nucleophilic substitution reactions: 2 steps

1. Leaving group leaves forming a positively charged carbocation (rate limiting step)

*The rate of rxn depends only on the concentration of the substrate

rate = k [R-L]

R-L is the alkyl group containing the leaving group

*Anything that accelerates the formation of the carbocation increase the rate of rxn

2. Nucleophile attacks the carbocation (unstable)

*results in substitution product

SN2 reaction

-bimolecular nucleophilic substitution reactions

- only 1 step (concerted reaction)

-nucleophile attacks the compound at the same time as the leaving group leaves

-Nucleophile actively displaces the leaving group in a backside attack

for this to occur, nucleophile must be strong & substrate can't be sterically hindered

-concentrations of substrate & nucleophile have role in determining the rate --> rate = k[Nu][R-L]

-Position of the substituents around the substrate carbon is inverted

acetyl group

COCH3

Biologically important carboxylic acids include pyruvic acid, citric acid, and the C-terminus of amino acid chains. Which of the following carboxylic acids will be the most acidic?

A. CH3CHClCH2COOH

B. CH3CH2CCl2COOH

C. CH3CH2CHClCOOH

D. CH3CH2CH2COOH

B.

carboxylic acids and acidity

carboxylic acids and their derivatives increase in acidity as the number of electron withdrawing groups increase. the closer in proximity to the acid functionality is to the electronegative group

is OH a better nucleophile or electrophile

nucleophile

thioester

sulfonyl

urea

azide

Which of the following elements is MOST likely to be a strong nucleophile?

A. Hydroxide ion

B. Water

C. Ethanol

D. Tert-butanol

A.