Ch' 14 Alcohols, Phenols, and Ethers

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Ch. 14Alcohols, Phenols, and Ethers

• Milbank High School

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Chapter Objectives

• 1.What is the general structure for an alcohol? A
  phenol? An ether?  
• 2.What are functional groups? Why are they useful
  in the study of organic chemistry? 
• 3.What structural feature is used to classify
  alcohols as primary, secondary, or tertiary?  
• 4.How are alcohols named by the common and IUPAC
  systems?  
• 5.Why are the boiling points of alcohols higher
  than those of ethers and alkanes of similar molar
  masses?  

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Objectives Cont

• 6.Why are alcohols and ethers of four carbons or
  less soluble in water while comparable alkanes
  are not?  
• 7.How are alcohols prepared from alkenes? What is
  Markovnikov's rule?  
• 8.How do various alcohols affect the human body?
    
• 9.What are the major reactions of alcohols?
• 10.What product is formed by the oxidation of a
  primary alcohol? A secondary alcohol? A tertiary
  alcohol?

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Objectives Cont

• 11.Describe the structure and uses of some common
  polyhydric alcohols.
• 12.Describe the structure and uses of some
  phenols.
• 13.How does the structural difference between
  alcohols and ethers affect their physical
  characteristics and reactivity?
• 14.How are simple ethers named? Describe the
  structure and uses of some ethers.

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Sec. 14.1General Formulas and Functional Groups

• Two of the three families contain a hydroxyl
  group (OH)
• Alcohols
• Phenols
• Ethers
• Often made from alcohols and phenols
• All are considered organic derivatives of water.

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General Formulas

• Bent molecule
• Central oxygen atom
• Hydrogen and alkyl group attached (R) or an aryl
  group (Ar)

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General Formulas Cont

• Alcohols
• R-O-H
• Phenols
• Ar-OH
• Benzene ring with an OH
• Ethers
• R-O-R

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Functional Groups

• Group of atoms which confers characteristic
  properties on a family of organic compounds
• OH
• COOH
• Alkanes none

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Sec. 14.2 Classification and Nomenclature of
Alcohols

• Properties of alcohols depend on the arrangement
  of the carbon atoms of the molecule
• Primary (1) carbon atom
• Secondary (2) carbon atom
• Tertiary (3) carbon atom

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Classification and Nomenclature of Alcohols

• Primary Alcohol
• RCH2OH
• Secondary Alcohol
• R2CHOH
• Tertiary Alcohol
• R3COH

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IUPAC Naming

• Name the longest continous chain of carbons
  containing the OH group
• Number which carbon the OH is attached to
• End name in ol
• If more than one hydroxyl group, use suffixes
  diol, -triol, etc.

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Physical Properties of Alcohols

• Replacement of hydrogen with a hydroxyl group
  greatly changes properties
• Not as homologous as alkanes
• Higher boiling points
• Due to strong intermolecular attractions
• Solubility
• The more compact the molecule is, the more
  soluble it is
• 4-5 carbons or lesssoluble in water

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Sec. 14.4Preparation of Alcohols

• Hydration Reactions

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Markovnikovs Rule

• The hydroxyl group goes on the carbon with fewer
  hydrogens

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Production of alcohols

• Methanol
• 1.7 billion gallons produced a year
• Used in formaldehyde, acetic acid, fuels (MTBE),
  silicones, refrigerants

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Production of Alcohols

• Ethanol
• Produced from sugars or starches by fermentation
• C6H10O5 ? C6H12O6? 2CH3CH2OH 2CO2
• (Enzymes as catalysts)
• Its the alcohol thats found in those certain
  beverages that people shouldnt drink

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Production of Alcohols Cont

• Wines
• 12 ethanol
• Champagnes
• 14-20 ethanol
• Beers
• 4 ethanol
• Whiskey
• 50 ethanol
• Proof spirit alcoholic content of a beverage,
  twice that of the alcohol content by volume
  (whiskey 100 proof)

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Sec. 14.5Physiological Effects of Alcohols

• LD50 (Lethal dose to 50 of a population)
• Tested on animals
• Varies per species though
• See table 14.5

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Methanol

• Can cause permanent blindness or death in high
  amounts
• Vapors are very dangerous as well

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Ethanol

• Toxic to humans
• Acute poisoning kills several hundred a year
  (drinking contests)
• Long term poisioning
• Most serious drug problem in US
• 40 times more addicts than heroin

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Isopropyl Alcohol

• Rubbing alcohol
• Rapid evaporation
• Antiseptic
• More toxic than ethanol, but induces vomitting
• Used for the manufacture of acetone

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Sec. 14.6Chemical Properties of Alcohols

• Reactions
• Occur on the functional groups
• May involve hydrogen atoms as well
• Dehydration
• Oxidation

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Dehydration

• Removal of water
• Sulfuric acid as a catalyst
• Produces
• Ether (excess ROH) water
• Alkene (excess H2SO4) water

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Oxidation

• Result depends on if alcohol is primary,
  secondary, or tertiary
• Primary
• Produces an aldehyde
• Then goes through further oxidation to produce a
  carboxylic acid
• Secondary
• Produces a ketone
• Tertiary
• No reaction
• Cant break the carbon-carbon bond

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Oxidation Cont
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Sec. 14.7 Multifunctional Alcohols Glycols and
Glycerol

• More than one hydroxyl group
• Polyhydric groups
• Dihydric alcohols
• Trihydric alcohols

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Glycols

• Dihydric alcohols
• 1,2 ethanediol (ethylene glycol)
• HOCH2CH2OH
• Two hydroxyl groupsextensive intermolecular
  hydrogen bonding
• Higher boiling point
• Used as anti-freeze

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Glycerol

• Most important trihydric alcohol
• Syrupy liquid
• Nontoxic, product of the hydrolysis of fats and
  oils
• Nitroglycerin
• Detonates on slight impact
• Reaction produces temps of 3000 C and pressures
  above 2000 atm

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Sec. 14.8Phenols

• Slightly acidic
• Neutralized by strong bases

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Phenols

• Used as
• Antiseptic
• Disinfectants
• First used was pure phenolproved to be too toxic
• Methyl derivatives
• Cresols
• Creosote

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Phenols

• Dihydroxybenzenes
• Components of biochemical molecules

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Sec. 14.9Ethers

• Derivatives of water
• Both hydrogen atoms are replaced
• Naming
• Symmetrical
• Name groups attached and add ether

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Properties

• Quite inert
• Although react violently in the air
• Low boiling pointsno hydrogen bonds
• Diethyl ether
• Forms a peroxide in air
• First general anesthetic