ALCOHOLS, PHENOLS and ETHERS Chemistry 21A Dr. Dragan Marinkovic Functional group of an alcohol...

ALCOHOLS, PHENOLS and ETHERS

Chemistry 21A Dr. Dragan Marinkovic

Functional group of an alcohol molecule

ethanolethyl alcohol

propan-2-ol, 2-propanol, iso, isopro, isoprop, rubbing alcohol, orthe abbreviation IPA – isopropyl alcohol)

C3H7OH

C2H5OHR-OH



cholesterol

The best source is probably Mentha arvensis, Corn Mint, whose oil is up to 85% (-)-menthol.

Menthol is a major component of mint.

High-density lipoprotein (HDL)



A fatty alcohol with two double bonds, bombykol (tr-10,cis-12-hexadecadien-1-ol), was also shown to be excreted as a very strong attractive substance by the female of silk-worm (Bombyx mori).

Glycerin, glycerine, propane-1,2,3-triol

The bombyx mori silk moth

Bombykol The sex pheromone of the silk moth



H O H H O HH O H

R O H O H R O R

O

CH3 CH2

CH2

OH

propan-1-ol

OH

water waterwater

alcohol phenol ether

O

diethyl ether(ether)

diphenyl ether

-OHhydroxyl group

phenol group

ether group

R~alkyl group



Nomenclature of Alcohols1. Alcohols are named by finding the longest continues carbon chain and changing the ending to –ol (e.g., methanol, ethanol, propanol, etc.). 2. With unsaturated alcohols, two endings are needed, one for the double or triple bond and one for the hydroxyl group. The –ol suffix is last and takes precedence in the numbering. 3. If the hydroxyl group is directly attached to an aromatic ring, the compound is named as a phenol. 4. If the hydroxyl group occurs in a carboxylic acid, aldehyde, or ketone, it is named as a substituent (hydroxy) because the former functionalities have higher priority. 5. The common names for the alcohols are the alkane chain named as a substituent followed by the word alcohol (e.g., methyl alcohol, ethyl alcohol, etc.)

CH3

OH

CH3

CH2

OHCH3

CH

2

CH2

OH

CH3

CH CH3

OH


propan-2-ol, 2-propanol, propan-1-ol, 1-propanol, methanolmethyl alcohol



CH3

CH

2

CH2

CH

2

OH CH3

CH C

H2

CH3

OH

CH3

CH C

H2

OH

CH3

CH3 OH

CH3

CH3

C

1-butanol

n-butyl alcohol

2-butanol

sec-butyl alcohol2-methyl-1-propanol 2-methyl-2-propanol

C4H9OH alcohols

isobutyl alcohol tert-butyl alcohol

OHCH

2

CH2

OHOH

CH

2

CH C

H2

OH

OH

OH

OHOH

OH OH

OHethanediolethylene glycol

1,2,3-propanetriol glycerin

trans-3-methylcyclohexanol

1-methylcyclopentanol

OHCH3



OH OHOH

OHOH

Cl Cl

Cl

phenol 3-methylphenol 4-ethylphenol

2,4,6-trichlorophenol benzyl alcohol

alcohol



CH3

CH

2

CH2

CH

2

OH CH3

CH C

H2

CH3

OH

CH3

CH C

H2

OH

CH3

CH3 OH

CH3

CH3

C

1-butanol

n-butyl alcohol

2-butanol

sec-butyl alcohol2-methyl-1-propanol 2-methyl-2-propanol

isobutyl alcohol tert-butyl alcohol

primary alcohol primary alcoholsecondary alcohol tertiary alcohol

OH

trans-3-methylcyclohexanol

OHCH

2

CH2

OH

OHOH

ethanediolethylene glycol 1-methylcyclopentanol

OHCH3



CH3CH2OCH2CH3 CH3CH2CH2CH2OH

BP = 34.5ºC BP = 117.2ºC

d = 0.7138 g/mL d = 0.8098 g/mL

insoluble in water

soluble in water

Water has an unusually high boiling point because of the hydrogen bonds between the H2O molecules. Alcohols can form similar hydrogen bonds.

The difference in boiling points between alkanes

and alcohols with the same number of carbon atoms decreases when

the total number of carbons increases (i.e. with the increase of hydrophobic character of alcohols).

As a result, alcohols have boiling points that are much higher than alkanes with similar molecular weights. The boiling point of ethanol, for example, is 78.5ºC, whereas propane, with about the same molecular weight, boils at -42.1ºC.



Solubilities of Alcohols in Water

Formula NameSolubility in Water (g/100 g)

CH3OH methanol infinitely soluble

CH3CH2OH ethanol infinitely soluble

CH3(CH2)2OH propanol infinitely soluble

CH3(CH2)3OH butanol 9

CH3(CH2)4OH pentanol 2.7

CH3(CH2)5OH hexanol 0.6

CH3(CH2)6OH heptanol 0.18

CH3(CH2)7OH octanol 0.054

CH3(CH2)9OH decanol insoluble in water

OH

OH

OH

OH

OH

OH

hydrophobic part of the molecule

hydrophilic part of the molecule



As the length of the alcohol increases, the effect of hydrogen bonding decreases and hydrophobic forces become dominant.

The difference in boiling points between alkanes and alcohols with thw same number of carbon atoms decreases when the total number of carbons increases (i.e. with the increase of hydrophobic character of alcohols).



dehydration reaction

CH3

CH

2

CH2

OHCH3

CH

2

CH2

OH CH3

CH

2

CH2

OCH3

CH

2

CH2

H2SO4

+

synthesis of ethers



CH3 CH2

OH CH3 O

H

CH3 O

OH

ethanol acetaldehyde acetic acid

oxydation oxydation



CH3 CH CH3

OH

CH3 CH3

O

isopropyl alcohol(2-propanol)

dimethyl ketone(acetone)

oxydation

R' OH

R

R"

CH3 OH

CH3

CH3

oxydation

oxydation

no reaction

no reaction

secondaryalcohol

tertiaryalcohol




C2H5OH

C6H12O6 → 2C2H5OH + 2CO2

yeast

C2H5OH + O2 → CH3COOH + H2O

CH3 CH2

OHCH2 CH2

70 atm

300oCethylene(ethene)

Made from corn and other crops(fermentation)

Pure 100% ethanol has an octane rating of 113. Adding 10% ethanol to gasoline raises the overall octane by 2 to 3 points. Lower BTU value than gasoline

For most of human history, acetic acid, in the form of vinegar, has been made by acetic acid bacteria of the genus Acetobacter.



CO + 2H2 CH3OH

CH3OH → H2C=O → HCOOH

heat, pressure, catalyst

methanol formaldehyde formic acid

Aqueous solution of formaldehyde is called formalin used for storing specimens and cadavers.

Methanol is produced naturallyin the anaerobic metabolism ofmany varieties of bacteria

About 40% of methanol is converted to formaldehyde, and from there into products as diverse as plastics, plywood, paints, explosives, and permanent press textiles.

common laboratory solvent

traditional denaturant for ethanol, thus giving the term methylated spirit

Drag racers and mud racers also use methanol as their primary fuel source.



propan-2-ol, 2-propanol, iso, isopro, isoprop, rubbing alcohol, orthe abbreviation IPA – isopropyl alcohol)

C3H7OH

Ethylene glycolMonoethylene glycolMEG1,2-ethanediol

widely used as an automotive antifreeze

odorless, colorless, syrupy, sweet tasting, toxic liquid

propylene glycol, 1,2-propanediol, 1,2-Dihydroxypropane, methyl ethyl glycol (MEG), methylethylene glycol, PG, Sirlene, Dowfrost

moisturizer in medicines,cosmetics, food, toothpaste, mouth wash, and tobacco products



In foods and beverages, glycerol serves as a humectants, solvent and sweetener, and may

help preserve foods. It is also used as filler in commercially prepared low-fat foods (e.g.,

cookies), and as a thickening agent in liqueurs. Glycerol also

serves as a way, along with water, to preserve certain types of leaves.

Glycerol is also used as a sugar substitute. In this regard, it has approximately 27 calories per teaspoon and is 60% as sweet as sucrose. Although it has about the same food energy as table

sugar, it does not raise blood sugar levels, nor does it feed the bacteria that form plaques and cause dental cavities. As a food additive, glycerol is also known as E number E422.

Example of an unsaturated fat triglyceride.

Glycerin, glycerine, propane-1,2,3-triol



OH

+ NaOH

ONa

+ H2O

SA SB WB WA

water insoluble water soluble

OH

+ NaHCO3 NR phenol < H2CO3

CH4 < NH3 < HCCH < ROH < H2O < phenols < H2CO3 < RCOOH < HF



Joseph Lister, 1st Baron Lister, (1827 – 1912) was an English surgeon who promoted the idea of sterile surgery while working at the Glasgow Royal Infirmary. He successfully introduced carbolic acid (phenol) to sterilize surgical instruments and to clean wounds, which led to reduced post-operative infections and made surgery safer for patients.

2-Benzyl-4-chlorophenol is an ingredient in Lysol.

2-Phenylphenol, or ortho-phenylphenol, is an ingredient in Lysol, and is an agricultural fungicide.



Butylated hydroxytoluene (BHT), also known as butylhydroxytoluene, is a organic compound that is primarily used as an antioxidant food additive (E number E321) as well as in cosmetics, pharmaceuticals, jet fuels, rubber, petroleum products, and embalming fluid

2,6-di-tert-butyl-4-methylphenol; 2,6-di-tert-butyl-p-cresol (DBPC); butylated hydroxytoluene; BHT

4-Chloro-3,5-dimethylphenol, or chloroxylenol, is a nonirritating topical antiseptic used in a number of antibacterial soaps.



Raspberry ketone is a natural phenolic compound that is the primary aroma compound of red raspberries. It is used in perfumery, in cosmetics, and as a food additive to impart a fruity odor.

4-hexylbenzene-1,3-diol

4-Hexylresorcinol is a chemical compound with anaesthetic, antiseptic and antihelmintic properties.It can be used topically on small skin infections, or as an ingredient in throat lozenges.

Anthelmintics or antihelminthics are drugs that expel parasitic worms (helminths) from the body, by either stunning or killing them. They may also be called vermifuges (stunning) or vermicides (killing).



PHENOLS are next-generation anti-oxidant found throughout nature in some of the healthiest foods. PHENOLS are the common health-giving link that ties together foods such as Red Wine, Green Tea, Dark Chocolate, and Super-Berries.

Molecular structure of apigenin, a polyphenol antioxidant

A polyphenol antioxidant is a type of antioxidant containing a polyphenolic substructure. In human health these compounds, numbering over 4000 distinct species, are thought to be instrumental in combating oxidative stress, a process associated with some neurodegenerative diseases and some cardiovascular diseases.



R O R

O

ether

O

diethyl ether(ether)

diphenyl ether

ether group dimethyl ether, an aerosol spray propellant

A common low boiling solvent (b.p. 34.6°C), and an early anaesthetic.

An aryl ether and a major constituent of the essential oil of anise seed.

Anisole (methoxybenzene)

Polyethylene glycol (PEG)

Polyethylene glycol has a low toxicity and is used in a variety of products. It is the basis of a number of laxatives (such as Movicol and polyethylene glycol 3350, or MiraLax or GlycoLax). It is the basis of many skin creams, as cetomacrogol, and sexual lubricants,



Physical Properties: The polar nature of the C-O bond (due to the electronegativity difference of the atoms ) results in intermolecular dipole-dipole interactions. An ether cannot form hydrogen bonds with other ether molecules since there is no H to be donated (no -OH group) Ethers can be involved in H-bonding with systems able to donate H (e.g. water). The implications of these effects are:

lower melting and boiling points compared to analogous alcohols solubility in aqueous media similar to analogous alcohols.

CH3CH2OCH2CH3 CH3CH2CH2CH2OH

BP = 34.5ºC BP = 117.2ºC

d = 0.7138 g/mL d = 0.8098 g/mL

insoluble in water

soluble in water



Ethers can act as a hydrogen-bond acceptor, as shown in the figure below. But, they can't act as hydrogen-bond donors. As a result, ethers are less likely to be soluble in water than the alcohol with the same molecular weight.

The absence of an -OH group in an ether also has important consequences for its chemical properties. Unlike alcohols, ethers are essentially inert to chemical reactions. They don't react with most oxidizing or reducing agents, and they are stable to most acids and bases, except at high temperatures. They are therefore frequently used as solvents for chemical reactions.However, ethers are generally extremely FLAMMABLE and tend,If exposed to air for longer periods of time, to form EXPLOSIVE PEROXIDES.



A thiol is a compound that contains the functional group composed of a sulfur atom and a hydrogen atom (-SH). Being the sulfur analogue of an alcohol group (-OH), this

functional group is referred to either as a thiol group or a sulfhydryl group. More traditionally, thiols are often referred to as mercaptans.

The preferred method (used by the IUPAC) is to add the suffix -thiol to the name of the alkane. The method is nearly identical to naming an alcohol. Example: CH3SH would be methanethiol. An older method, the word mercaptan replaces alcohol in the name of the equivalent alcohol compound. Example: CH3SH would be methyl mercaptan. (CH3OH would be methyl alcohol)



Cysteine Cystine, showing disulfide bond

Many thiols are colorless liquids having an odor resembling that of garlic. The odor of thiols is often strong and repulsive, particularly for those of low molecular weight

Natural gas distributors began adding various forms of pungent thiols, originally ethanthiol, to natural gas, which is naturally odorless, after the deadly 1937 New London School explosion in New London, Texas. Most gas odorants utilized in the world contain mixtures of mercaptans and sulfides, with t-butyl mercaptan as the main odor constituent.

CH3 SH

CH3

CH3

(oxydation)



Diallyl disulfide (4,5-dithia-1,7-octadiene) is an organosulfur compound, along with

diallyl trisulfide and diallyl tetrasulfide it is one of the principal components of the distilled oil of garlic.



2R-SH + (O) → R-S-S-R + H2O

2CH3SH + (O) → CH3-S-S-CH3

thiol disulfide

2CH3SH + Pb2+ → CH3-S-Pb-S-CH3 + 2H+

Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle.

ALCOHOLS, PHENOLS and ETHERS Chemistry 21A Dr. Dragan Marinkovic Functional group of an alcohol...

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