alcohol

Alcohols

• Alcohols:– hydrocarbon derivatives in which one or more of

the H atoms has been replaced by a hydroxyl group (alcohol functional group)

C - O - H OR C - OH

Hydroxyl groups

Alcohols

• Alcohols are named in the exact same manner as alkanes, alkenes, and alkynes except:– To find the base name, drop the “e” from the

name of the corresponding alkane and add “ol”• Use the carbon number to identify the position of the

alcohol.

CH3CH2CH2OH

1-propanol2-butanol

CH3CH2CHCH3

OH

Alcohols

• The position of the alcohol in the chain has a significant impact on the reactivity of the alcohol.

• A primary alcohol (1o) is an alcohol in which the OH group is attached to a carbon which is bonded to only 1 other C atom.

– CH3CH2OH

Alcohols

• A secondary alcohol (2o) is an alcohol in which the OH group is attached to a carbon which is bonded to two other carbon atoms.

– CH3CHCH3

OH

– CH3CH2CHCH2CH3

OH

Alcohols

• A tertiary alcohol (3o) is an alcohol in which the OH group is attached to a C which is bonded to three other carbon atoms.

CH3 CH2CH3

CH3CCH3 CH3CH2CCH3

OH OH

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Naming Alcohols

A carbon compound that contain -OH (hydroxyl) group

In IUPAC name, the -e in alkane name is replaced with -ol.

CH4 methane

CH3OH methanol (methyl alcohol)

CH3CH3 ethane

CH3CH2OH ethanol (ethyl alcohol)

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More Names of Alcohols

IUPAC names for longer chains number the chain from the end nearest the -OH group.

CH3CH2CH2OH propan-1-ol

OH CH3CHCH3 propan-2-ol

CH3 OH CH3CHCH2CH2CHCH3 5-methylhexan-2-ol

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Some Typical Alcohols OH “rubbing alcohol” CH3CHCH3

propan-2-ol (isopropyl alcohol)

antifreeze HO-CH2-CH2-OH

ethane-1,2-diol (ethylene glycol) OH

glycerolHO-CH2-CH-CH2OH

propane-1,2,3-triol

Anti-

freez

e

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Phenols

IUPAC name for benzene with a hydroxyl groupMany are used as antiseptics and disinfectants

OH

Phenol

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Ethers

• Contain an -O- between two carbon groups• Ethers are named by adding the suffix oxy to the

shorter chain and attaching it to the longer chain’s alkane name.

CH3-O-CH3 methoxymethane

CH3-O-CH2CH3 methoxyethane

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LecturePLUS Timberlake 13

ThiolsMany thiols have disagreeable odorsUsed to detect gas leakFound in onions, oysters, garlic and oysters

Onions CH3CH2CH2-SH 1-propanethiolGarlic CH2= CHCH2-SH 2-propene-1-thiolSkunk spray

CH3 trans-2-butene-1-thiol

CH = CH

CH2SH