3 Classification of Alcohols Alcohols are classifiedBy the number of alkyl groups attached to the carbon bonded to the hydroxyl.As primary (1°), secondary (2°), or tertiary (3°).Primary (1º) Secondary (2º) Tertiary (3º) 1 group groups 3 groups H CH CH | | |CH3—C—OH CH3—C—OH CH3—C—OH | | | H H CH3
4 Learning Check (P) primary, (S) secondary, or (T) tertiary. OH | Classify each alcohol as(P) primary, (S) secondary, or (T) tertiary.OH|1. CH3—CH—CH2—CH32. CH3—CH2—CH2—OH3. CH3—CH2—C—CH2—CH3CH3
5 Solution | 1. CH3—CH—CH2—CH3 (S) secondary OH|1. CH3—CH—CH2—CH3 (S) secondary2. CH3—CH2—CH2—OH (P) primary3. CH3—CH2—C—CH2—CH3 (T) tertiaryCH3
6 Naming Alcohols The names of alcohols In the IUPAC system replace -e of alkane name with -ol.that are common names use the name of the alkyl group followed by alcohol.Formula IUPAC Common NameCH4 methaneCH3─OH methanol methyl alcoholCH3─CH3 ethaneCH3─CH2─OH ethanol ethyl alcohol
7 More Names of AlcoholsIn IUPAC names for longer carbon chains, the chain isnumbered from the end nearest the ─OH group.CH3─CH2─CH2─OH propanolOH│CH3─CH─CH2─CH butanolCH OH│ │CH3─CH─CH2─CH2─CH─CH methyl-2-hexanol
11 Learning Check Write the structure of the following: A. 3-pentanol B. ethyl alcoholC methylcyclohexanol
12 Solution Write the structure of the following: A. 3-pentanol OH | CH3—CH2—CH—CH2—CH3B. ethyl alcohol CH3 —CH2 —OHC methylcyclohexanol
13 Naming Phenols To name a phenol with two substituents, Assign C-1 to the carbon attached to the –OH.Number the ring to give the lowest numbers.Use prefixes o, m, and p for common names.Phenol chlorophenol bromophenol(m-chlorophenol) (p-bromophenol)
14 Phenols in Medicine Phenol Is the IUPAC name for benzene with a hydroxyl group.Is used in antiseptics and disinfectants.phenol resorcinol hexylresorcinol
26 Ethers Ethers Contain an ─O─ between two carbon groups. That are simple are named by listing the alkyl names in alphabetical order followed by etherCH3─O─CH3 CH3─CH2─O─CH3dimethyl ether ethyl methyl ether
27 IUPAC Names for EthersIn the IUPAC system, the shorter alkyl group and the oxygen are named as an alkoxy group attached to the longer alkane.methoxy propaneCH3—O—CH2—CH2—CH3Numbering the longer alkane gives1-methoxypropane
28 Ethers as Anesthetics Anesthetics Inhibit pain signals to the brain. Such as ethyl ether CH3─CH2─O─CH2─CH3 were used for over a century, but caused nausea and were flammable.Developed by 1960s were nonflammable.Cl F F Cl F H│ │ │ │ │ │H─C─C─O─C─H H─C─C─O─C─HF F F H F HEthane(enflurane) Penthrane
29 MTBE Methyl tert-butyl ether CH3 │ CH3─O─C─CH3 Is one of the most produced organic chemicals.Is a fuel additiveIs used to improve gasoline combustion.Use is questioned since the discovery that MTBE has contaminated water supplies.
30 Learning Check Draw the structure of each compound. A. diethyl ether B. ethyl methyl etherC. 2-methoxybutane
31 Solution Draw the structure of each compound. A. diethyl ether CH3—CH2—O—CH2—CH3B. ethyl methyl ether CH3—CH2—O—CH3C. 2-methoxybutaneO—CH3|CH3—CH—CH2—CH3
32 Dioxins Dioxins are A group of ethers that are highly toxic. Formed during forest fires and as industrial by-products.Often carcinogenic.2,4,5-trichlorophenoxyacetic acid ,3,7,8-tetrachlorodibenzodioxin(2,4,5-T; agent orange) (TTCC, “dioxin”)
47 Dehydration of Alcohols Dehydration of an alcohol occursWhen heated with an acid catalyst.With the loss of —H and —OH from adjacent carbon atoms.H OH| | H+, heatH—C—C—H H—C=C—H + H2O| | | |H H H Halcohol alkene
48 Learning Check Write the equations for the reactions when 2-propanol undergoes:1. combustion2. dehydration
50 Oxidation and Reduction In the oxidation of an organic compoundThere is an increase in the number of C—O bonds.There is a loss of H.In the reduction of an organic compoundThere is an decrease in the number of C—O bonds.There is a gain of H.
52 Oxidation of Primary (1) Alcohols When a primary alcohol is oxidized [O],One H is removed from the –OH.Another H is removed from the carbon bonded to the OH.An aldehyde is produced.[O]Primary alcohol AldehydeOH O| [O] ||CH3—C—H CH3—C—H + H2O|HEthanol Ethanal(ethyl alcohol) (acetaldehyde)
53 Oxidation of Secondary (2) Alcohols When a secondary alcohol is oxidized [O],One H is removed from the –OH.Another H is removed from the carbon bonded to the OH.A ketone is produced.[O]secondary alcohol ketoneOH O│ [O] ║CH3—C—CH CH3—C—CH3 + H2O│H2-propanol (isopropyl alcohol) propanone(dimethyl ketone,“acetone”)
54 Oxidation of Tertiary (3)Alcohols Tertiary alcohols do not readily oxidize [O]Tertiary alcohol no reactionOH│ [O]CH3─C─CH3 no product│CH no H on the C-OH to oxidize2-methyl-2-propanol
55 Learning Check Select the compound that would result for each reaction of CH3—CH2—CH2—OH.O ||1) CH3—CH=CH ) CO2 + H2O ) CH3—CH2—C—HA. H+, heatB. [O]C. O2, heat
56 Solution CH3—CH2—CH2—OH A. H+, heat 1) CH3—CH=CH2 O || B. [O] 3) CH3—CH2—C—HC. O2, heat 2) CO2 + H2O
57 Oxidation of Ethanol in the Body Ethanol is oxidized by enzymes in the liver.Aldehyde product impairs coordination.O O║ ║CH3─CH2─OH CH3─C─H CH3─C─OHethyl alcohol acetaldehyde acetic acid2CO2 + H2O
64 Carbonyl Group in Aldehydes and Ketones A carbonyl groupIn an aldehyde is attached to at least one H atom.In a ketone is attached to two carbon groups.
65 Naming Aldehydes An aldehyde Has an IUPAC name in which the -e in the alkane name is changed to -al.Has a common name for the first four aldehydes that use the prefixes form (1C), acet (2C), propion (3C), and butyr (4C), followed by aldehyde.O O O║ ║ ║H−C−H CH3−C−H CH3−CH2−C−Hmethanal ethanal propanal(formaldehyde) (acetaldehyde) (propionaldehyde)
68 Naming Ketones Ketones are named In the IUPAC system by replacing the -e in the alkane name with one. The carbonyl carbon is indicated by a number.With a common name by indicating the alkyl groups attached to the carbonyl group in alphabetical orderfollowed by ketone.O O║ ║CH3−C−CH CH3−C−CH2−CH3propanone butanone(dimethyl ketone) (ethyl methyl ketone)
72 Learning CheckClassify each as an aldehyde (1), ketone (2), alcohol (3),or ether (4).O║A. CH3─CH2─C─CH3 B. CH3─O─CH3CH O OH│ ║ │C. CH3─C─CH2─C─H D. CH3─CH─CH3│CH3
73 Solution Classify each as an aldehyde (1), ketone (2), alcohol (3), or ether (4).O║A. CH3─CH2─C─CH3 B. CH3─O─CH3(2) ketone (4) etherCH O OH│ ║ │C. CH3─C─CH2─C─H D. CH3─CH─CH3│CH3(1) aldehyde (3) alcohol
74 Learning Check Name each of the following: O ║ 1. CH3─CH2─CH2─CH2─C─H 2. Cl─CH2─CH2─C─H3. CH3─CH2─C─CH3
81 Polar Carbonyl Group The polar carbonyl group Provides dipole-dipole interactions.+ + -C=O C=ODoes not have H on the oxygen atom.Cannot form hydrogen bonds.
82 Boiling Points Aldehydes and ketones have Polar carbonyl groups (C=O). + -C=OAttractions between polar groups.+ + -C=O C=OHigher boiling points than alkanes and ethers of similar mass.Lower boiling points than alcohols of similar mass.
83 Comparison of Boiling Points 58Aldehydes and ketones haveHigher boiling points than alkanes and ethers of similar mass.Lower boiling points than alcohols of similar mass.
84 Learning Check Select the compound in each pair that would have the Higher boiling point.A. CH3—CH2—CH3 or CH3—CH2—OHB.C. CH3—CH2—OH or CH3—O—CH3
101 Enantiomers Have same mp, bp, same chemistry Except: reaction with other chiral molecules
102 Smell: Caraway Spearmint R-(-)-carvone S-(+)-carvone (Dill) (Manderine Orange Peel)SpearmintPass around models: Are they the same or different?Pass around spearmint & caraway oils: Are they the same or different?Explain receptors (G-protein) and how enantiomers fit (hand in glove)
103 Enantiomers Have same mp, bp, same chemistry Except: reaction with other chiral moleculesExcept: rotation of plane of polarized light
104 Learning CheckIdentify each as a chiral or achiral compound.
105 Solution Identify each as a chiral or achiral compound. chiral achiral chiral
106 Fischer Projections A Fischer projection Is a 2-dimensional representation of a 3-dimensional molecule.Places the most oxidized group at the top.Uses vertical lines in place of dashes for bonds that go back.Uses horizontal lines in place of wedges for bonds that come forward.