Organic Nomenclature Organic Compounds • Organic Compounds - any covalently bonded compound containing carbon (except carbonates and oxides) Organic Compounds Contain carbon Have covalent bonds Have low melting points Have low boiling points Burn in air (oxygen) Are soluble in nonpolar solvents Form large molecules General Characteristics of Organic Molecules • Organic molecules exhibit three different types of hybridization at the carbon center: – sp3 hybridized carbons for tetrahedral geometries; – sp2 hybridized carbons for trigonal planar geometries; and – sp hybridized carbons for linear geometries. Stabilities of Organic Molecules • Carbon forms very strong bonds between H, O, N, and halogens. • Carbon also forms strong bonds with itself. • Therefore, C can form stable long chain or ring structures. • Bond strength increases from single to double to triple bond. • Bond length decreases in the same direction. Hydrocarbons • Hydrocarbons - Organic compounds that contain only carbon & hydrogen • Alkanes - contain only single covalent bonds • Alkenes - contain one or more carbon - carbon double bond • Alkynes - contain one or more carbon-carbon triple bond Saturated & Unsaturated Hydrocarbons • Saturated hydrocarbons – contain only single carbon-carbon bonds (alkanes) • Unsaturated hydrocarbons – contain double carbon-carbon bonds (alkenes) or triple carbon-carbon (alkynes) bonds Formulas • Alkanes = CnH2n+2 • Alkenes = CnH2n • Alkynes = CnH2n-2 Nomenclature • Must memorize prefixes • To name, look at the formula for the hydrocarbon • Determine if it is an alkane, alkene, or alkyne • Use the prefix for the number of carbons • Add ending (ane, ene, yne) Prefix # of carbon atoms Meth- 1 Eth- 2 Prop- 3 But- 4 Pent- 5 Hex- 6 Hept- 7 Oct- 8 Non- 9 Dec- 10 Example • • • • • • Name C3H8 This falls under the equation CnH2n+2 Therefore it is an alkane Since n=3 we will use the prefix prop Since it is an alkane we will use the ending ane propane Alkanes Contain C and H only Contain single bonds C-C Have 4 bonds to every carbon (C) atom Are nonpolar Complete Structural Formulas Show the bonds between each of the atoms H H HCH H C H H H CH4 , methane Drawing structures: it’s all good H 2-butene C CH H H 3 H C C C C H H H H H3C H C H CH H3C CH3 CH CH3 H3C CH CH CH3 H3C This is called the “condensed structure” On a test, choose a method that shows all Hs CH3CH=CHCH3 Using brackets can also shorten some formulas: CH3(CH2)4CH3 vs. CH3CH2CH2CH2CH2CH3 More Alkanes H H H H C C H H H Condensed Structural Formulas H H H C C C H H H H CH3 CH3 Ethane CH3 CH2 CH3 Propane IUPAC Names Name # carbons Structural Formula Methane 1 CH4 Ethane 2 CH3CH3 Propane 3 CH3CH2CH3 Butane 4 CH3CH2CH2CH3 Pentane 5 CH3CH2CH2CH2CH3 Naming: common vs. IUPAC • Common names used in the 1800’s are still used for some compounds today: O O H C H OH Formic acid C C Acetylene H C H3C CH3 Acetone • The International Union of Pure and Applied Chemistry (IUPAC) was established in 1900s • Frequent revisions to nomenclature • Systematic method allows an infinite number of compounds to be named given a few rules IUPAC NAMES Name # carbons Structural Formula Hexane 6 CH3CH2CH2CH2CH2CH3 Heptane 7 CH3CH2CH2CH2CH2CH2CH3 Octane 8 CH3CH2CH2CH2CH2CH2CH2CH3 Nonane 9 CH3 CH2 CH2CH2CH2CH2CH2CH2CH3 Decane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 Learning Check Alk1 A. What is the condensed formula for H H H H H C C C C H H H H H B. What is its molecular formula? C. What is its name? Branched Alkanes CH3 CH3CHCH3 methyl groups CH3 CH3 CH3CHCH2CHCH3 Alkyl Groups Branches on carbon chains H H C CH3 methyl H H H H C C H H CH3CH2 ethyl Naming Branched Alkanes CH3 methyl branch CH3CH2CH2CHCH2CH3 6 5 4 3 2 1 Count Naming Branched Alkanes CH3 methyl branch CH3CH2CH2CHCH2CH3 6 5 4 3 2 1 Count 3-Methylhexane on third C CH3 six carbon chain group Naming side chains CH CH 3 H H3C C • Names are made up of: side chains, root • 2,3-dimethylpentane C H3 CH • Root is the longest possible HC chain • Must contain multiple bonds if present • Add -yl to get name of side chain H C 3 • Common side chains include: CH CH3- methyl CH3CH2ethyl * CH3CH2CH2- propyl (CH3)2CHisopropyl • “iso” (branched) is not an IUPAC convention • Br- (bromo), Cl- (chloro), F- (fluoro), I- (iodo) C H3 CH CH3 Naming side chains Example: use the rules to name: CH2 CH3 CH2 C CH2 CH3 CH2 C CH3 CH3 Rule 1: choose the correct ending ene Naming side chains CH2 CH3 CH2 C CH2 CH3 CH2 C CH3 CH3 Rule 2: longest carbon chain ene • Alkenes and Alkynes – Alkenes are hydrocarbons with at least one double carbon to carbon bond. • To show the presence of the double bond, the –ane suffix from the alkane name is changed to –ene. – The alkenes are unsaturated with respect to hydrogen • This means it does not have the maximum number of hydrogen atoms as it would if it were an alkane (a saturated hydrocarbon). – Naming is similar to naming alkanes except: • The longest continuous chain must contain the double bond. • The base name now ends in –ene. • The carbons are numbered so as to keep the number for the double bond as low as possible. • The base name is given a number which identifies the location of the double bond. – An alkyne is a hydrocarbon with at least one carbon to carbon triple bond. – Naming an alkyne is similar to the alkenes, except the base name ends in –yne. Alkenes Carbon-carbon double bonds Names end in -ene H2C=CH2 H2C=CH-CH3 ethene (ethylene) propene (propylene) cyclohexene Alkynes Carbon-carbon triple bonds Names end in -yne HCCH HCC-CH3 ethyne(acetylene) propyne Naming Alkenes and Alkynes When the carbon chain has 4 or more C atoms, number the chain to give the lowest number to the double or triple bond. 1 2 3 4 CH2=CHCH2CH3 CH3CH=CHCH3 CH3C CCH3 1-butene 2-butene 2-butyne Numbering carbons Q- draw pentene A- Where’s the bond? H C 3 5 1 We number C atoms H H 1-pentene C C C C H H H H 4 2 3 2 4 1 5 H • Thus, naming compounds with multiple bonds is more complex than previously indicated • Only if 2+ possibilities exist, are #s needed • Always give double bond the lowest number • Q - Name these H C 2H 4 H3 C C 2-butene C CH3 Ethene H H3C CH3 3-nonyne Multiple multiple bonds H 3C CH3 2,3-heptadiene H3C C C C C C C 2,4,6-nonatriyne • • • • CH2 CH3 Give 1st bond (1st point of difference) lowest # include di, tri, tetra, penta, etc. before ene/yne Comma between #s, hyphen between #-letter You do not need to know ene + yne H H C H C C C HC 2-butyne H H2C C CH2 CH 1,2,4-pentatriene CH3CH2CH2CH=C=CH2 1,2-hexadiene H H Cyclic structures H H H H C C C H • Cyclic structures are circular C C • Have “cyclo” in name H H H H • Benzene is not a cyclic structure • cyclopentane Q- Draw these (note: carbons in a double bond should be consecutive- 1 and 2, 5 and 6, etc.): cyclobutene 1,3-cyclopentadiene cyclopropane H Naming side chains CH2 CH3 CH2 C CH2 CH3 CH2 C CH3 CH3 Rule 3: attach prefix (according to # of C) 1-hexene ene Naming side chains CH2 CH3 CH2 C CH2 CH3 CH2 C CH3 CH3 Rule 4: Assign numbers to each carbon 1-hexene Naming side chains CH2 CH2 CH3 1 CH3 CH2 C 2 5 CH2 C 3 4 6 CH3 CH3 Rule 4: Assign numbers to each carbon 1-hexene Naming side chains ethyl CH2 CH2 CH3 1 CH3 CH2 C 2 5 6 CH2 C 3 CH3 methyl 4 CH3 methyl Rule 5: Determine name for side chains 1-hexene Naming side chains ethyl CH2 CH2 CH3 1 CH3 CH2 C 2 5 CH2 C 3 6 CH3 methyl CH3 methyl 4 Rule 6: attach name of branches 2-ethyl-4,4-dimethyl-1-hexene Learning Check HA3 Write the IUPAC name for each of the following unsaturated compounds: A.CH3CH2CCCH3 CH3 CH3 B. CH3C=CHCH3 C. Solutions HA3 Write the IUPAC name for each of the following unsaturated compounds: A.CH3CH2CH=CHCH3 2-pentene CH3 CH3 B. CH3C=CHCH3 2-methyl-2-butene C. 3-methylcyclopentene Numbering priority • 1. functional groups • 2. double and triple bonds • 3. substituents • Once all groups have been numbered, place them in alphabetical order in the final compounds name. • Numbers are separated by commas • Names and numbers are separated by dashes. • Use mathematical prefixes for multiple substituent's. • Often times you will find shorter branches of carbons off of the • longest (main or parent) chain. These branches are known as • alkyl groups, branches or substituents. • They are named using the same prefixes as before but using -yl • as a suffix on the name. • Naming Branched Chain Alkanes • 1. Find the longest continuous chain of hydrocarbon (remember • that they may bend around corners). This is your parent chain. • 2. Number the parent chain beginning from the end closest to the • first branch. • 3. Identify the alkyl groups and the carbon number on the parent • chain they are attached to. • 4. List the alkyl groups in alphabetical order and the number • where the attachment occurs. (Separate numbers from words • with hyphens). • 5. Finally, list the parent name. • Ex: • CH3CH2CHClCH2CH=CHCHBrCH3 • 2-bromo-5-chloro-3-octene Learning Check Alk4 A. CH3 CH3 CH3CHCH2CHCH3 B. CH3 CH3 CH3CH2CHCH2CCH2CH3 CH3 Solution Alk4 A. CH3 CH3 CH3CHCH2CHCH3 B. CH3 2,4-dimethylpentane CH3 CH3CH2CHCH2CCH2CH3 CH3 3,3,5-trimethylheptane Learning Check Alk5 Write a condensed structure for A. 3,4-dimethylheptane B. 2,2-dimethyloctane Solution Alk5 A. 3,4-dimethylheptane CH3 CH3CH2CHCHCH2CH2CH3 CH3 B. 2,2-dimethyloctane CH3 CH3CCH2CH2CH2CH2CH2CH3 CH3 Cycloalkanes Cyclopropane CH2 CH2 CH2 Cyclobutane CH2 CH2 CH2 CH2 More Cycloalkanes Cyclopentane CH2 CH2 CH2 CH2 CH2 Cyclohexane CH2 CH2 CH2 CH2 CH2 CH2 Naming Cycloalkanes with Side Groups Number of Naming side groups 1. Side group name goes in front of the cycloalkane name. 2. Number the ring in the direction that gives the lowest numbers to the side groups. Cycloalkanes with Side Groups CH3 methylcyclopentane CH3 CH3 1,2-dimethylcyclopentane CH3 CH3 1,2,4-trimethylcyclohexane CH3 Learning Check Alk8 CH 3 CH 3 CH 3 CH 3 CH3 Solution Alk8 CH3 1,2-dimethylcyclobutane CH3 CH3 methylcyclopentane CH3 1,3-dimethylcyclohexane CH3 Aromatic Compounds and Benzene Aromatic compounds contain benzene. Benzene, C6H6 , is represented as a six carbon ring with 3 double bonds. Two possible can be drawn to show benzene in this form. H H H H H H H H H H H H Benzene Structure The structures for benzene can also be written as a single structure where the alternating double bonds are written as a circle within the ring. Benzene structure Aromatic Compounds in Nature and Health Many aromatic compounds are common in nature and in medicine. CHO COOH COOCH3 CH3 CH3 CH3CHCH2 CHCOOH OCH3 OH Aspirin Vanillin Ibuprofen Naming Aromatic Compounds Aromatic compounds are named with benzene as the parent chain. One side group is named in front of the name benzene. CH3 methylbenzene (toluene) Cl chlorobenzene Naming Aromatic Compounds When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) are also used. Cl CH3 Cl CH3 Cl 1,2-dimethylbenzene 1,3-dichlorobenzene (ortho-dimethylbenzene) (meta-dichlorobenzene) CH3 1-chloro-4-methylbenzene (para-chloromethylbenzene) Some Common Names Some substituted benzene rings also use a common name. Then naming with additional more side groups uses the ortho-, meta-, para- system. CH3 OH CH3 Cl Toluene (Methylbenzene) meta-chlorotoluene (meta-chloromethylbenzene) phenol (hydroxybenzene) Learning Check Alk9 Select the names for each structure: Cl 1. Chlorocyclohexane 2. Chlorobenzene 3. 1-chlorobenzene CH 3 CH 3 1. Meta-methyltoluene 2. Meta-dimethylbenzene 3. 1,3-dimethylbenzene Solution Alk9 Select the names for each structure: Cl 2. Chlorobenzene CH 3 1. Meta-methyltoluene 2. Meta-dimethylbenzene 3. 1,3-dimethylbenzene CH 3 Learning Check Alk10 Write the structural formulas for each of the following: A. 1,3-dichlorobenzene B. Ortho-chlorotoluene Solution Alk10 Write the structural formulas for each of the following: Cl A. 1,3-dichlorobenzene B. Ortho-chlorotoluene Cl CH3 Cl Isomers Types of isomerism Isomerism Structural isomerism Stereoisomerism Geometric isomerism Optical isomerism Isomers- structural Same molecular formula Same number and types of atoms Different arrangement of atoms isomers • Isomers- all the possible spatial arrangements for a given hydrocarbon. • Follow these steps= • 1. start with the longest straight chain. • 2. shorten the chain by one carbon, and add that extra carbon as a methyl group in all the possible positions starting from the left and moving right. • 3. check each time to make sure the names don’t repeat. • 4. shorten the chain by 2 carbons. Add each carbon separately as a methyl to all the possible places. Keep your numbering system correct. Then add the 2 carbons as an ethyl group following the same pattern. • Ex: Try heptane and octane Examples of Isomers The formula C4H10 has two different structures CH3 CH3CH2CH2CH3 Butane CH3CHCH3 2-methylpropane When a CH3 is is used to form a branch, it makes a new isomer of C4H10. H H H H H H H H H H H C C C C C C C C C C H H H H H H H H H H Decane Draw 4 isomers of decane c c c c c c c c cc c c c c c c ccc c c cc c c c c ccc c c c c c c c cc c H Learning Check Alk6 Write 3 isomers of C5H12 and name each. Solution Alk6 CH3CH2CH2CH2CH3 pentane CH3 CH3CHCH2CH3 2-methylbutane CH3 CH3CCH3 CH3 2,2-dimethylpropane Learning Check Alk7 Write the structural formulas of 3 isomers that have the formula C5H12. Name each. Solution Alk7 Write the structural formulas of 3 isomers that have the formula C5H12. Name each. CH3CH2CH2CH2CH3 CH3 CH3CHCH2CH3 2-methylbutane pentane CH3 CH3CCH3 CH3 2,2-dimethylpropane Cis trans isomers • This also occurs around the double or triple bonds in straight chains. • Ex: C4H8 has 4 isomers Cis and Trans Isomers Double bond is fixed Cis/trans Isomers are possible CH3 CH3 CH = CH cis CH3 CH = CH trans CH3 Look at these models Cis -2-butene Trans – 2 - butene Two isomers are not interchangeable. • Carbon 2 & 3 joined by double bond. • No free rotation. • Bonds would have to be broken and reformed. • +270 kJ mol-1 energy needed to break this bond. • Insufficient energy available at room temperature. cis... Cis-2- butene • Different names needed to identify isomers. • Substituent groups on the same side of double bond. • Cis -2-butene ...and trans. Trans-2- butene • “trans” means other side or cross over e.g. trans Atlantic, transplant, trans…..! • Substituents on opposite sides of double bond. Different compounds- different properties. • • • • • 1-butene Cis-2-butene Trans-2-butene 2-methylpropene ( isobutene) Cis is also called the Z isomer for the German word zusammen = together • Trans are also called the E isomer for the word entegen = opposite. Draw all the isomers • For – C5H10 and C6H12 and name them include all cis /trans isomers Organic Chemistry: Functional Groups Functional Groups Part of an organic molecule where chemical reactions take place Composed of an atom or group of atoms Replace a H in the corresponding alkane Provide a way to classify organic compounds Functional Groups Class Alcohol Functional group R – OH Ether R — O — R’ Aldehyde O || R—C—H Ketone O || R — C — R’ Carboxylic acid O || — C — OH Ester O || R — C — O — R’ Amine R’ | R — N — R’’ Some Types of Functional Groups Haloalkane -F, -Cl, -Br CH3Cl Alcohol -OH CH3OH Ether CH3-O-CH3 -O- O O Aldehyde C H Ketone O O C CH3CCH3 CH3CH More Functional Groups Carboxylic acid -COOH CH3COOH Ester -COO- CH3COOCH3 Amine -NH2 CH3NH2 Amide -CONH2 CH3CONH2 Haloalkanes An alkane in which one or more H atoms is replaced with a halogen (F, Cl, Br, or I) CH3Br 1-bromomethane (methyl bromide) Br CH3CH2CHCH3 2-bromobutane Cl chlorocyclobutane Hydrocarbons: Basic Concepts Topic 27 Organic Compounds Containing Halogens • Any organic compound that contains a halogen substituent is called a halocarbon. • If you replace any of the hydrogen atoms in an alkane with a halogen atom, you form an alkyl halide. Hydrocarbons: Basic Concepts Topic 27 Organic Compounds Containing Halogens • An alkyl halide is an organic compound containing a halogen atom covalently bonded to an aliphatic carbon atom. • The first four halogens— fluorine, chlorine, bromine, and iodine—are found in many organic compounds. Hydrocarbons: Basic Concepts Topic 27 Organic Compounds Containing Halogens • For example, chloromethane is the alkyl halide formed when a chlorine atom replaces one of methane’s four hydrogen atoms. Hydrocarbons: Basic Concepts Topic 27 Organic Compounds Containing Halogens • An aryl halide is an organic compound containing a halogen atom bonded to a benzene ring or other aromatic group. • The structural formula for an aryl halide is created by first drawing the aromatic structure and then replacing its hydrogen atoms with the halogen atoms specified. Learning Check HA1 Name the following: Br Cl Cl Solution HA1 Name the following: Br bromocyclopentane Cl 1,3-dichlorocyclohexane Cl Substituents List other attached atoms or group in alphabetical order Br = bromo, Cl = chloro Cl Br CH3CHCH2CHCH2CH2CH3 4-bromo-2-chloroheptane Learning Check HA2 The name of this compound is: Cl CH3 CH3CH2CHCH2CHCH3 1) 2,4-dimethylhexane 2) 3-chloro-5-methylhexane 3) 4-chloro-2-methylhexane Solution HA2 The name of this compound is: Cl CH3 CH3CH2CHCH2CHCH3 3) 4-chloro-2-methylhexane Haloalkanes as Anesthetics Halothane (Fluothane) F Cl F C C Br F H Fluothane is a haloalkane that is widely used as an anesthetic, which is a compound that decreases the ability of the nerve cells to conduct pain. Ozone Layer Ozone layer Stratosphere (10-30 miles Above Earth) Chlorofuorocarbons (CFCs and the Ozone Layer ozone O3 layer absorbs most of the sun’s harmful radiation. CFCs - chlorofluorocarbons - are depleting that ozone layer. CFCs are used as Freons in refrigeration, air conditioning, and foam insulation. Their use in spray cans is no longer allowed. Alcohols • Alcohols have a OH group attached to a C somewhere along the chain. • The ending changes to “ol” • If there are 2 OH groups the are referred to as a “diol” • The OH group has to be identified using the IUPAC numbering system • Ex: CH2ClCHOHCHClCH3 • 1,3-dichloro-2-butanol Hydrocarbons: Basic Concepts Topic 27 Alcohols • An oxygen-hydrogen group covalently bonded to a carbon atom is called a hydroxyl group (—OH). • An organic compound in which a hydroxyl group replaces a hydrogen atom of a hydrocarbon is called an alcohol. • The general formula for an alcohol is ROH. 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 CH3CH3 methanol (methyl alcohol) ethane CH3CH2OH ethanol (ethyl alcohol) Ethanol CH3CH2OH Acts as a depressant Kills or disables more people than any other drug 12-15 mg/dL ethanol metabolized by a social drinkers in one hour 30 mg/dL ethanol metabolized by an alcoholic in one hour. Alcohol in Some Products % Ethanol Product 50% 40% 15-25% 12% 3-9% Whiskey, rum, brandy Flavoring extracts Listerine, Nyquil, Scope Wine, Dristan, Cepacol Beer, Lavoris More Names of Alcohols IUPAC names for longer chains number the chain from the end nearest the -OH group. CH3CH2CH2OH 1-propanol OH CH3CHCH3 CH3 2-propanol OH CH3CHCH2CH2CHCH3 5-methyl-2-hexanol Some Typical Alcohols OH “rubbing alcohol” CH3CHCH3 2-propanol (isopropyl alcohol) antifreeze HO-CH2-CH2-OH 1,2-ethanediol (ethylene glycol) OH glycerol HO-CH2-CH-CH2OH Learning Check Al 2 Name the following alcohols: A. OH CH3CHCHCH2CH3 CH3 OH B. Solution Al 2 Name the following alcohols: A. OH 3-methyl-2-pentanol CH3CHCHCH2CH3 CH3 OH B. cyclobutanol Reactions of Alcohols Combustion CH3OH + 2O2 Dehydration H OH CO2 + 2H2O + Heat H+, heat H-C-C-H H-C=C-H + H2O H H alcohol H H alkene Aldehydes and Ketones In an aldehyde, an H atom is attached to a carbonyl group O carbonyl group CH3-C-H In a ketone, two carbon groups are attached to a carbonyl group O CH3-C-CH3 carbonyl group aldehydes • Aldehydes contain a CHO attached to the end of a carbon chain The C has a double bonded O and a single bonded H attached to it. Since it is at the end of a chain there is no need to number. • The ending changes to “al” • Ex: CH3CHICH2CH2CHICHO • 2,5-diiodohexanal Naming Aldehydes IUPAC Replace the -e in the alkane name -al Common Add aldehyde to the prefixes form (1C), acet (2C), propion(3), and butry(4C) O O O II H-C-H CH3-C-H CH3CH2C-H methanal ethanal propanal (formaldehyde) (acetaldehyde) (propionaldehyde) Aldehydes as Flavorings O O CH CH O CH=CH CH HO OCH3 Benzaldehyde (almonds) Vanillin (vanilla beans) Cinnamaldehyde (cinnamon) Glucose is an aldehyde O H C H C OH HO C H H C OH H C OH CH 2 OH glucose Ketones • Ketones have a C=O bond embedded within a chain . • The IUPAC system of numbering applies here and the “e” of the chain gets replaced with a “one” ending • O • ║ • Ex: CH3CH2CCH2CH2CH2CH2CH3 • 3-octanone Naming Ketones In the IUPAC name, the -e in the alkane name is replaced with -one In the common name, add the word ketone after naming the alkyl groups attached to the O carbonyl group O CH3 -C-CH3 2- Propanone O II CH3-C-CH2-CH3 2-Butanone (Dimethyl ketone) (Ethyl methyl ketone) Cyclohexanone Ketones OO Butter flavor CH3-C-C-CH3 butanedione O Clove flavor CH3-C-CH2CH2CH2CH2CH3 2-heptanone Fructose is a Ketone CH 2OH C HO O C H H C OH H C OH CH 2OH D-Fructose Ketones as Hormones CH2OH O CH3 O OH CH3 O Cortisone Learning Check AK 1 Classify each as an aldehyde (1), ketone (2) or neither(3). O II A. CH3CH2CCH3 B. CH3-O-CH3 O CH3 O C. CH3-C-CH2CH CH3 D. Solution AK 1 Classify each as an aldehyde (1), ketone (2) or neither(3). O II A. CH3CH2CCH3 2 B. CH3-O-CH3 3 CH3 O O C. CH3-C-CH2CH 1 CH3 D. 2 Learning Check AK 2 Name the following O A. CH3CH2CCH3 CH3 O II C. CH3-C-CH2CH CH3 O B. Solution AK 2 O O A. CH3CH2CCH3 B. 2-butanone (ethyl methyl ketone) CH3 O C. CH3-C-CH2CH CH3 2,2-dimethylbutanal cyclohexanone Learning Check AK 3 Draw the structural formulas for each: A. 3-Methylpentanal B. 2,3-Dichloropropanal C. 3-Methyl-2-butanone Solution AK 3 Draw the structural formulas for each: CH3 A. 4-Methylpentanal O CH3CHCHCH2CH Br O B. 2,3-Dibromopropanal Br-CH2CHCH O C. 3-Methyl-2-butanone CH3CHCCH3 CH3 ethers • Have an O atom within the carbon chain itself. In other words C-O-C. • Components of the chain on both sides of the O have to be named. • Ethers have the general formula ROR′. • No numbering system is needed since the chain is broken. • The name remains the same just add the ending ether Ethers • The simplest ether is one in which oxygen is bonded to two methyl groups. • Note the relationship between methanol and methyl ether in the following diagram. Ethers • Contain an -O- between two carbon groups • Simple ethers named from -yl names of the attached groups and adding ether. CH3-O-CH3 dimethyl ether CH3-O-CH2CH3 ethyl methyl ether • Ex: CH3OCH2CH2CH2CH2CH3 • Methyl-n-pentyl ether The “n” signifies that the carbons are in a straight chain with no branches. Ethers as Anesthetics Anesthetics inhibit pain signals to the brain CH3CH2-O-CH2CH3 used for over a century (Morton, 1846) Causes nausea and is highly flammable 1960s developed nonflammable anesthetics Cl F F Cl F H H-C-C-O-C-H F F H-C-C-O-C-H F HF H Ethane(enflurane) Penthrane MTBE Methyl tert-butyl ether CH3 CH3-O-C-CH3 CH3 Second in production or organic chemicals Additive to improve gasoline performance Carboxylic acids • These compounds end with a COOH group where the C has a double bonded O and a single bonded OH • The ending of the parent chain changes from “ane” etc. to “oic” and add the word acid • Ex: CH3CH2CH2COOH • Butanoic acid Carboxyl Group Carboxylic acids contain the carboxyl group on carbon 1. O CH3 — C—OH = CH3—COOH carboxyl group Naming Carboxylic Acids Formula IUPAC alkan -oic acid Common prefix – ic acid HCOOH methanoic acid formic acid CH3COOH ethanoic acid acetic acid CH3CH2COOH CH3CH2CH2COOH propanoic acid butanoic acid propionic acid butyric acid Naming Rules • Identify longest chain • (IUPAC) Number carboxyl carbon as 1 • • CH3 | CH3 — CH—CH2 —COOH IUPAC 3-methylbutanoic acid Learning Check CA1 Give IUPAC and common names: A. CH3COOH CH3 | B. CH3CHCOOH Solution CA 1 A. CH3COOH ethanoic acid; acetic acid CH3 | B. CH3CHCOOH 2-methylpropanoic acid; Properties • Carboxylic acids are weak acids CH3COOH + H2O • Neutralized by a base CH3COOH + NaOH CH3COO– + H3O+ CH3COO– Na+ + H2O Phenols IUPAC name for benzene with a hydroxyl group Many are used as antiseptics and disinfectants OH Phenol Phenols in Medicine OH OH OH OH OH CH2CH2CH2CH2CH2CH3 Phenol Resorcinol (antiseptic) 4-Hexylresorcinal (antiseptic) Compounds with Oxygen Atoms Alcohols -OH hydroxyl CH3-OH CH3CH2-OH OH OH Phenols Ethers -O- CH3-O-CH3 Learning Check Al1 Classify each as an alcohol (1), phenol (2), or an ether (3): A. _____ CH3CH2-O-CH3 C. _____ CH3CH2OH OH B. _____ CH3 Solution Al 1 Classify each as an alcohol (1), phenol (2), or an ether (3): A. __3__ CH3CH2-O-CH3 C. __1__ CH3CH2OH OH B. _ 2__ CH3 Thiols Contain the functional group -SH Named by adding thiol to the name of the longest carbon chain Number the -SH group in longer chains CH3-SH methanethiol CH3-CH2SH ethanethiol SH CH3-CH-CH3 2-propanethiol Thiols Many thiols have disagreeable odors Used to detect gas leak Found in onions, oysters, garlic and oysters Onions CH3CH2CH2-SH 1-propanethiol Garlic CH2= CHCH2-SH 2-propene-1-thiol Skunk spray CH3 trans-2-butene-1-thiol CH = CH CH2SH Amines • Organic compounds of nitrogen N • Classified as primary, secondary, tertiary CH3 CH3 CH3—NH2 CH3—NH CH3—N — CH3 1° 2° 3° Naming Amines IUPAC aminoalkane CH3CH2NH2 aminoethane (ethylamine) Common alkylamine CH3—NH —CH3 N-methylaminomethane (dimethylamine) NH 2 NH CH3 NH2 | CH3CHCH3 2-aminopropane (isopropylamine) Aniline N-methylaniline Learning Check AM1 Give the common name and classify: A. CH3NHCH2CH3 CH3 | B. CH3CH2NCH3 Solution AM1 A. CH3NHCH2CH3 ethylmethylamine, 2° CH3 | B. CH3CH2NCH3 ethyldimethylamine, 3° Alkaloids • Physiologically active nitrogen-containing compounds • Obtained from plants • Used as anesthetics, antidepressants, and stimulants • Many are addictive Nicotine CH3 N Nicotine, leaves of tobacco plant Caffeine O CH3 O CH3 N N N N CH3 Caf f e in e , cof f e e b e an s an d t e a Procaine CH3CH2 O N CH2CH2 O C NH2 CH3CH2 Procaine (novocaine), painkiller Leaning Check AM2 Write a structural formula for A. 1-aminopentane B. 1,3-diaminocyclohexane Solution AM2 A. 1-aminopentane CH3CH2CH2CH2CH2-NH2 B. 1,3-diaminocyclohexane NH2 NH2 Amides Derivatives of carboxylic acids where an amino (-NH2) group replaces the –OH group . O O CH3 — C—OH carboxylic acid ethanoic acid CH3 — C—NH2 amide ethanamide Naming Amides Alkanamide from acid name O HC–NH2 methanamide (IUPAC) formamide (common) O CH3CH2C–NH2 propanamide (IUPAC) propionamide(common) Naming Amides with N-Groups O CH3C–NHCH3 N-methylethanamide (IUPAC) N-methylacetamide (common) O CH3CH2C–N(CH3)2 N,N-dimethylpropanamide N,N-dimethylpropionamide Aromatic Amides O O C NH2 C NHCH3 Benzamide N -methylbenzamide Learning Check AM3 Name the following amides: O A. CH3CH2CH2C–NH2 B. O CH3C–N(CH2CH3)2 Solution AM3 O A. CH3CH2CH2C–NH2 butanamide; butryamide (common) O B. CH3C–N(CH2CH3)2 N,N-diethylethanamide; N,N-diethylacetamide Learning Check AM4 Draw the structures of A. Pentanamide B. N-methylbutyramide Solution AM4 A. Pentanamide O CH3CH2CH2CH2C–NH2 B. N-methylbutyramide O CH3CH2CH2C–NHCH3 Esters In and ester, the H in the carboxyl group is replaced with an alkyl group O CH3 — C—O —CH3 = CH3—COO —CH3 ester group Esters in Plants Esters give flowers and fruits their pleasant fragances and flavors. Naming Esters • Name the alkyl from the alcohol –O• Name the acid with the C=O with –ate acid alcohol O methyl CH3 — C—O —CH3 Ethanoate methyl ethanoate (IUPAC) (acetate) methyl acetate (common) Some Esters and Their Names Flavor/Odor Raspberries HCOOCH2CH3 ethyl methanoate (IUPAC) ethyl formate (common) Pineapples CH3CH2CH2 COOCH2CH3 ethyl butanoate (IUPAC) ethyl butyrate (common) Learning Check CA 2 Give the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears. O CH3 — C—O —CH2CH2CH3 Solution CA2 O propyl CH3 — C—O —CH2CH2CH3 proply ethananoate (IUPAC) propyl acetate (common) Learning Check CA 3 Draw the structure of the following compounds: A. 3-bromobutanoic acid B. Ethyl propionoate conformations • 3 dimensional molecular structures interrelated by rotations about the bonds. • Ex. Ethane C2H6 • Can be described as eclipsed and staggered. • See handout Hydrogenation Adds a hydrogen atom to each carbon atom of a double bond H H H–C=C–H + H2 Ni H H H–C–C–H H H ethene ethane Products of Hydrogenation Adding H2 to vegetable oils produces compounds with higher melting points Margarines Soft margarines Shortenings (solid) Learning Check HA4 What is the product of adding H2 (Ni catalyst) to 1-butene? Solution HA4 What is the product of adding H2 (Ni catalyst) to 1-butene? Ni CH2=CHCH2CH3 + H2 CH3CH2CH2CH3 Adding Halogens Halogens also add to the double bond of an alkene. H2CCH2 + Cl2 Cl Cl H2C CH2 Br Br CH3C CCH2CH3 + Br2 CH3C CCH2CH3 Br Br Learning Check HA5 Write the product of the following addition reactions: CH3CH=CHCH3 + H2 + Br2 Solution HA5 Write the product of the following addition reactions: CH3CH=CHCH3 + H2 + Br2 CH3CH2CH2CH3 Br Br Unsaturated Fatty Acids Fatty acids in vegetable oils are omega-6 acids (the first double bond occurs at carbon 6 counting from the methyl group) A common omega-6 acid is linoleic acid CH3CH2CH2CH2CH2CH=CHCH2CH=CH(CH2)7COOH 6 linoleic acid, a fatty acid Trans Fats In vegetable oils, the unsaturated fats usually contain cis double bonds. During hydrogenation, some cis double bonds are converted to trans double bonds (more stable) causing a change in the fatty acid structure If a label states “partially” or “fully hydrogenated”, the fats contain trans fatty acids. Trans Fats In the US, it is estimated that 2-4% of our total Calories is in the form of trans fatty acid. trans fatty acids behave like saturated fatty acids in the body. Several studies reported that trans fatty acids raise LDL-cholesterol. Some studies also report that trans fatty acid lower HDL-cholesterol The trans fatty acids controversy will continue to be debated. Fats and Atheroschlerosis Inuit people of Alaska have a high fat diet and high blood cholesterol levels, but a very low occurrence of atherosclerosis and heart attacks. Fat in the Intuit diet was primarily from fish such as salmon, tuna and herring rather than from land animals (as in the American diet). Omega-3 Fatty Acids Fatty acids in the fish oils are mostly the omega-3 type (first double bond occurs at the third carbon counting from the methyl group). linolenic acid 18 carbon atoms CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH eicosapentaenoic acid (EPA) 20 carbon atoms CH3CH2(CH=CHCH2)5(CH2)2COOH Learning Check HA6 (1) Ture or (2) False A. ____ There are more unsaturated fats in vegetable oils. B. ____ Vegetable oils have more omega-3 oils than found in fish. C. ____ Hydrogenation of oils converts some cis-double bonds to trans- double bonds. D. ____ Animal fats have more saturated fats.