Organic Chemistry 1 Organic Chemistry The Chemistry of carbon compounds. 2 Organic Chemistry The Chemistry of carbon compounds. We will look at: (1) Naming of simple compounds. 3 Organic Chemistry The Chemistry of carbon compounds. We will look at: (1) Naming of simple compounds. (2) Some simple reactions. 4 Organic Chemistry The Chemistry of carbon compounds. We will look at: (1) Naming of simple compounds. (2) Some simple reactions. (3) Some simple properties. 5 Organic Chemistry The Chemistry of carbon compounds. We will look at: (1) Naming of simple compounds. (2) Some simple reactions. (3) Some simple properties. (4) Some applications will be discussed. 6 Naming simple organic compounds 7 Naming simple organic compounds Organic compounds are organized in different families, and each family has a root name. 8 Naming simple organic compounds Organic compounds are organized in different families, and each family has a root name. Compounds derived from the starting members in the family have their name based on the parent compound from which they are derived. 9 The key compounds for naming are the hydrocarbons. 10 The key compounds for naming are the hydrocarbons. There are three basic classifications and some important secondary classifications. 11 The key compounds for naming are the hydrocarbons. There are three basic classifications and some important secondary classifications. (1) Alkanes 12 The key compounds for naming are the hydrocarbons. There are three basic classifications and some important secondary classifications. (1) Alkanes (2) Alkenes 13 The key compounds for naming are the hydrocarbons. There are three basic classifications and some important secondary classifications. (1) Alkanes (2) Alkenes (3) Alkynes 14 Prefix system used to name inorganic compounds. This is also used for organic compounds to name the number of substituents. The base names for the alkanes with five or more C atoms are derived directly from these names. number prefix 1 2 3 4 5 6 7 8 9 10 mon* di tri tetra penta hexa hepta octa nona deca *Often not employed. 15 Prefix system used to name the number of carbon atoms in the longest chain of organic compounds. Note that the ones in blue do not follow from the first four prefixes in the previous table. These entries are sometimes termed the roots for the number of C atoms. number prefix 1 2 3 4 5 6 7 8 9 10 meth eth prop but pent hex hept oct non dec 16 Names for organic compounds break up into two groups: 17 Names for organic compounds break up into two groups: Non-systematic (trivial) 18 Names for organic compounds break up into two groups: Non-systematic (trivial) Systematic (This will be our focus, though some of the common names will be mentioned.) 19 Names for organic compounds break up into two groups: Non-systematic (trivial) Systematic (This will be our focus, though some of the common names will be mentioned.) Example: H2O The non-systematic name is water. The systematic name is dihydrogen oxide. 20 Number of bonds For the following atoms the typical number of bonds from each atom is as follows: Atom H C Number of bonds 1 4 21 Number of bonds For the following atoms the typical number of bonds from each atom is as follows: Atom H C O N Number of bonds 1 4 2 3 22 Number of bonds For the following atoms the typical number of bonds from each atom is as follows: Atom Number of bonds H 1 C 4 O 2 N 3 (Note: there are exceptions) 23 The Alkanes 24 The Alkanes As far as naming is concerned, the alkanes are the top priority family. 25 The Alkanes As far as naming is concerned, the alkanes are the top priority family. Many other names are based on the names used for this group of compounds. 26 The Alkanes As far as naming is concerned, the alkanes are the top priority family. Many other names are based on the names used for this group of compounds. The alkanes have the general formula CnH2n+2 where n = 1, 2, 3, …. 27 Formula CH4 Name methane 28 Formula CH4 CH3CH3 Name methane ethane 29 Formula CH4 CH3CH3 CH3CH2CH3 Name methane ethane propane 30 Formula CH4 CH3CH3 CH3CH2CH3 CH3CH2CH2CH3 Name methane ethane propane butane 31 Formula CH4 CH3CH3 CH3CH2CH3 CH3CH2CH2CH3 CH3CH2CH2CH2CH3 Name methane ethane propane butane pentane 32 Formula CH4 CH3CH3 CH3CH2CH3 CH3CH2CH2CH3 CH3CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH3 Name methane ethane propane butane pentane hexane 33 Formula CH4 CH3CH3 CH3CH2CH3 CH3CH2CH2CH3 CH3CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH2CH3 Name methane ethane propane butane pentane hexane heptane 34 Formula CH4 CH3CH3 CH3CH2CH3 CH3CH2CH2CH3 CH3CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH2CH3 CH3CH2CH2CH2CH2CH2CH2CH3 Name methane ethane propane butane pentane hexane heptane octane 35 Formula Name CH4 methane CH3CH3 ethane CH3CH2CH3 propane CH3CH2CH2CH3 butane CH3CH2CH2CH2CH3 pentane CH3CH2CH2CH2CH2CH3 hexane CH3CH2CH2CH2CH2CH2CH3 heptane CH3CH2CH2CH2CH2CH2CH2CH3 octane CH3CH2CH2CH2CH2CH2CH2CH2CH3 nonane 36 Formula Name CH4 methane CH3CH3 ethane CH3CH2CH3 propane CH3CH2CH2CH3 butane CH3CH2CH2CH2CH3 pentane CH3CH2CH2CH2CH2CH3 hexane CH3CH2CH2CH2CH2CH2CH3 heptane CH3CH2CH2CH2CH2CH2CH2CH3 octane CH3CH2CH2CH2CH2CH2CH2CH2CH3 nonane CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 decane 37 Formula CH4 Name methane 38 Formula CH4 CH3CH3 Name methane ethane 39 Formula CH4 CH3CH3 CH3CH2CH3 Name methane ethane propane 40 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 Name methane ethane propane butane 41 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 CH3(CH2)3CH3 Name methane ethane propane butane pentane 42 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 CH3(CH2)3CH3 CH3(CH2)4CH3 Name methane ethane propane butane pentane hexane 43 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 CH3(CH2)3CH3 CH3(CH2)4CH3 CH3(CH2)5CH3 Name methane ethane propane butane pentane hexane heptane 44 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 CH3(CH2)3CH3 CH3(CH2)4CH3 CH3(CH2)5CH3 CH3(CH2)6CH3 Name methane ethane propane butane pentane hexane heptane octane 45 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 CH3(CH2)3CH3 CH3(CH2)4CH3 CH3(CH2)5CH3 CH3(CH2)6CH3 CH3(CH2)7CH3 Name methane ethane propane butane pentane hexane heptane octane nonane 46 Formula CH4 CH3CH3 CH3CH2CH3 CH3(CH2)2CH3 CH3(CH2)3CH3 CH3(CH2)4CH3 CH3(CH2)5CH3 CH3(CH2)6CH3 CH3(CH2)7CH3 CH3(CH2)8CH3 Name methane ethane propane butane pentane hexane heptane octane nonane decane 47 Alkyl groups 48 Alkyl groups Formula Name 49 Alkyl groups Formula CH3 Name methyl 50 Alkyl groups Formula CH3 CH3CH2 Name methyl ethyl 51 Alkyl groups Formula CH3 CH3CH2 CH3CH2CH2 Name methyl ethyl n-propyl 52 Alkyl groups Formula CH3 CH3CH2 CH3CH2CH2 CH3(CH2)2CH2 Name methyl ethyl n-propyl n-butyl 53 Alkyl groups Formula CH3 CH3CH2 CH3CH2CH2 CH3(CH2)2CH2 CH3(CH2)3CH2 Name methyl ethyl n-propyl n-butyl n-pentyl 54 Alkyl groups Formula CH3 CH3CH2 CH3CH2CH2 CH3(CH2)2CH2 CH3(CH2)3CH2 Name methyl ethyl n-propyl n-butyl n-pentyl Ending change: ane root names) yl (or add yl to the 55 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. 56 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. Three other prefixes that occur commonly are: sec- short for secondary 57 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. Three other prefixes that occur commonly are: sec- short for secondary tert- short for tertiary 58 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. Three other prefixes that occur commonly are: sec- short for secondary tert- short for tertiary iso (no hyphen is used) 59 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. Three other prefixes that occur commonly are: sec- short for secondary tert- short for tertiary iso (no hyphen is used) Examples: H H H H H C C C C H H H H sec-butyl 60 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. Three other prefixes that occur commonly are: sec- short for secondary tert- short for tertiary iso (no hyphen is used) Examples: H H C H H H H H H H H C C C H H C C C C H H H H H H sec-butyl tert-butyl 61 In the previous list “n” stands for normal. In this case the bond is from the first carbon of the longest chain. Three other prefixes that occur commonly are: sec- short for secondary tert- short for tertiary iso (no hyphen is used) Examples: H H H C H H C H H H H H H H H H H C C C H H C C C H C C C C H H H H H H H H H sec-butyl tert-butyl isobutyl 62 The term isoalkane is used to denote a branched chain alkane with a methyl group attached to the penultimate carbon atom of the main chain. 63 The term isoalkane is used to denote a branched chain alkane with a methyl group attached to the penultimate carbon atom of the main chain. As the number of carbon atoms increase, the prefixes become less useful, because an increasingly large number of prefixes would be needed. In this case, the standard numbering scheme (described about nine slides later) is used. 64 Structures of some alkanes 65 Structures of some alkanes H H C H H 66 Structures of some alkanes H H C H H H H H C C H H H 67 Structures of some alkanes H H C H H H C H H H H H C C H H H H H C C H H H 68 Structures of some alkanes H H C H H H C H H H C H H H H C C H H H H H H H H H C C C C H C H H H H H H 69 Structures of some alkanes H H C H H H C H H H C H H H H C C H H H H H H H H H C C C C H C H H H H H H These are straight chain examples. 70 Structures of some alkanes H H C H H H C H H H C H H H H C C H H H H H H H H H C C C C H C H H H H H H These are straight chain examples. Note that the alkanes have only single bonds. 71 Branched alkanes 72 Branched alkanes H H H H H C C C C H H H CH3 H 73 Branched alkanes H H H H H C C C C H H H CH3 H 4 3 2 1 74 Branched alkanes H H H H H C C C C H H H CH3 H 4 3 2 1 2-methylbutane (the 2 is a bit redundant) 75 Branched alkanes H H H H H C C C C H H H CH3 H 4 3 2 1 2-methylbutane (the 2 is a bit redundant) Number the longest chain so as to give the lowest number to the substituent (in this case a methyl group) off the main chain. 76 H H H H H H C C C C C H H H CH3CH3H 77 H H H H H H C C C C C H H H CH3CH3H 5 4 3 2 1 78 H H H H H H C C C C C H H H CH3CH3H 2,3-dimethylpentane 5 4 3 2 1 79 H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 80 H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 Note: there is a methyl and an ethyl group off the main chain. 81 H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 1 2 3 4 5 6 7 8 Note: there is a methyl and an ethyl group off the main chain. 82 H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 8 7 6 5 4 3 2 1 5 and 6 bigger than 3 and 4 – so this is wrong numbering Note: there is a methyl and an ethyl group off the main chain. 83 H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 1 2 3 4 5 6 7 8 Note: there is a methyl and an ethyl group off the main chain. 84 3-methyl-4-ethyloctane (complexity order) H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 1 2 3 4 5 6 7 8 Note: there is a methyl and an ethyl group off the main chain. 85 3-methyl-4-ethyloctane (complexity order) 4-ethyl-3-methyloctane (alphabetical order) H H H H H H H H H C C C C C C C C H H H CH3CH2H H H H CH3 1 2 3 4 5 6 7 8 Note: there is a methyl and an ethyl group off the main chain. 86 Summary of the simple rules to name an alkane. Prefix + root + suffix 87 Ways of depicting an alkane (p. 578) 88 The impact of free rotation about carbon – carbon single bonds. 89 Exercise: Draw the structures of (1) 2,2,3-trimethylbutane (2) 4-ethyl-2-methylnonane (2-methyl-4-ethylnonane) (3) 2,4-dimethyloctane 90 Physical properties of the alkanes The series of straight-chain alkanes shows a very smooth gradation of physical properties. As the series is ascended, each additional CH2 group contributes a fairly constant increment to the boiling point and to the density – and to a lesser extent to the melting point. This makes it possible to estimate the properties of an unknown member of the series from those of its neighbors. 91 Alkenes 92 Alkenes These are hydrocarbons with at least one or more double bonds. 93 Alkenes These are hydrocarbons with at least one or more double bonds. The parent alkanes are used to name the alkene family of compounds. 94 Alkenes These are hydrocarbons with at least one or more double bonds. The parent alkanes are used to name the alkene family of compounds. The name ending change is: ane ene 95 alkane ethane alkene ethene structure H H C C H H 96 alkane ethane alkene ethene structure H H H propane propene H C C C C H H CH3 H 97 alkane butane alkene butene structure 98 alkane alkene structure butane butene In this case there are three possible compounds. 99 alkane alkene structure butane butene In this case there are three possible compounds. H 1-butene H C C H CH2 CH3 100 alkane alkene structure butane butene In this case there are three possible compounds. H 1-butene H The number 1 indicates on which carbon C C the double bond starts. H CH2 CH3 101 alkane alkene structure butane butene In this case there are three possible compounds. H 1-butene H The number 1 indicates on which carbon C C the double bond starts. H CH2 CH3 2- butene CH3 CH3 C C H H 102 alkane alkene structure butane butene In this case there are three possible compounds. H 1-butene H The number 1 indicates on which carbon C C the double bond starts. H CH2 CH3 2- butene CH3 CH3 C C H H H CH3 C C H CH3 103 alkane alkene structure butane butene In this case there are three possible compounds. H 1-butene H The number 1 indicates on which carbon C C the double bond starts. H CH2 CH3 2- butene cis-2-butene trans-2-butene CH3 CH3 C C H H H CH3 C C H CH3 104 Z and E isomers Some cases arise in which it is very difficult to name a compound unambiguously, e.g. 105 Z and E isomers Some cases arise in which it is very difficult to name a compound unambiguously, e.g. Br Cl C C I CH3 106 Z and E isomers Some cases arise in which it is very difficult to name a compound unambiguously, e.g. Br Cl Is this a cis or trans compound? C C I CH3 107 Z and E isomers Some cases arise in which it is very difficult to name a compound unambiguously, e.g. Br Cl Is this a cis or trans compound? C C I CH3 A way to sort out this problem is to use the symbols 108 Z and E isomers Some cases arise in which it is very difficult to name a compound unambiguously, e.g. Br Cl Is this a cis or trans compound? C C I CH3 A way to sort out this problem is to use the symbols Z (zusammen = together) 109 Z and E isomers Some cases arise in which it is very difficult to name a compound unambiguously, e.g. Br Cl Is this a cis or trans compound? C C I CH3 A way to sort out this problem is to use the symbols Z (zusammen = together) E(entgegen = opposite) 110 Rules 1. Compare the two groups on one carbon atom of the carbon-carbon double bond. 111 Rules 1. Compare the two groups on one carbon atom of the carbon-carbon double bond. 2. Assign the two groups priorities using the CahnIngold-Prelog rules for R and S configurations. 112 Rules 1. Compare the two groups on one carbon atom of the carbon-carbon double bond. 2. Assign the two groups priorities using the CahnIngold-Prelog rules for R and S configurations. 3. Repeat steps 1 and 2 for the second carbon of the carbon-carbon double bond. 113 Rules 1. Compare the two groups on one carbon atom of the carbon-carbon double bond. 2. Assign the two groups priorities using the CahnIngold-Prelog rules for R and S configurations. 3. Repeat steps 1 and 2 for the second carbon of the carbon-carbon double bond. 4. If the two groups of highest priority are on the same side of the double bond, we have the Z isomer. If the two groups are on opposite sides we have the E isomer. 114 Arrange the atoms in decreasing order of atomic number, e.g. I, Br, Cl, S, P, F, O, N, C, H 115 CH3 CH3 C C H H Z-2-butene 116 CH3 CH3 C C H H Z-2-butene H CH3 C C E-2-butene H CH3 117 CH3 CH3 C C H H Z-2-butene H CH3 C C E-2-butene H CH3 Cl Br C C I CH3 E-2-bromo-1-chloro-1-iodopropene 118 CH3 CH3 C C H H Z-2-butene H CH3 C C E-2-butene H CH3 Cl Br C C I E-2-bromo-1-chloro-1-iodopropene CH3 The group of highest priority on each C atom is circled. 119 CH3 CH3 C C H H Z-2-butene H CH3 C C E-2-butene H CH3 Cl Br C C I E-2-bromo-1-chloro-1-iodopropene CH3 The group of highest priority on each C atom is circled. 120 alkene ethene condensed formula CH2CH2 121 alkene ethene propene condensed formula CH2CH2 CH2CHCH3 122 alkene ethene propene 1-butene condensed formula CH2CH2 CH2CHCH3 CH2CHCH2CH3 123 alkene ethene propene 1-butene 2-butene condensed formula CH2CH2 CH2CHCH3 CH2CHCH2CH3 CH3CHCHCH3 124 alkene condensed formula ethene CH2CH2 propene CH2CHCH3 1-butene CH2CHCH2CH3 2-butene CH3CHCHCH3 Note: it would not be clear from the formula for 2butene whether this is the cis or trans compound. 125 alkene condensed formula ethene CH2CH2 propene CH2CHCH3 1-butene CH2CHCH2CH3 2-butene CH3CHCHCH3 Note: it would not be clear from the formula for 2butene whether this is the cis or trans compound. This is a reason why structures are very useful! 126 It is possible to have more than one double bond present. For example: H H C C H C H C H H 1,3-butadiene 127 Alkynes 128 Alkynes The alkynes have one or more triple bonds. 129 Alkynes The alkynes have one or more triple bonds. The ending change is: ane yne 130 Alkynes The alkynes have one or more triple bonds. The ending change is: ane yne The alkenes and the alkynes are referred to as unsaturated hydrocarbons. 131 Alkynes The alkynes have one or more triple bonds. The ending change is: ane yne The alkenes and the alkynes are referred to as unsaturated hydrocarbons. Unsaturated hydrocarbon: A hydrocarbon having one or more double or triple bonds. 132 alkane ethane alkyne ethyne structure H C C H 133 alkane ethane alkyne ethyne structure H C C H propane propyne H C C CH3 134 alkane ethane alkyne ethyne structure H C C H propane propyne H C C CH3 butane 1-butyne H C C CH2 CH3 135 alkane ethane alkyne ethyne structure H C C H propane propyne H C C CH3 butane 1-butyne 2-butyne H C C CH2 CH3 CH3 C C CH3 136 alkyne ethyne condensed formula C2H2 137 alkyne ethyne condensed formula C2H2 propyne CHCCH3 138 alkyne ethyne condensed formula C2H2 propyne CHCCH3 1-butyne CHCCH2CH3 139 alkyne ethyne condensed formula C2H2 propyne CHCCH3 1-butyne CHCCH2CH3 2-butyne CH3CCCH3 140 alkyne ethyne condensed formula C2H2 propyne CHCCH3 (Writing C3H4 would not be useful.) 1-butyne CHCCH2CH3 2-butyne CH3CCCH3 141 alkyne ethyne condensed formula C2H2 propyne CHCCH3 (Writing C3H4 would not be useful. Why?) 1-butyne CHCCH2CH3 2-butyne CH3CCCH3 142 Explanation of why C3H4 would not be useful. 143 Explanation of why C3H4 would not be useful. Clearly, this could be propyne. H C C CH3 144 Explanation of why C3H4 would not be useful. Clearly, this could be propyne. H C C CH3 But it could also be H C C C H H H 145 Explanation of why C3H4 would not be useful. Clearly, this could be propyne. H C C CH3 But it could also be H C C C H H H 1,2-propadiene 146 Explanation of why C3H4 would not be useful. Clearly, this could be propyne. H C C CH3 But it could also be H C C C H H H 1,2-propadiene (The numbering would be a bit redundant in this example.) 147 Cycloalkanes 148 Cycloalkanes The cyclo compounds have a ring of carbon atoms present in the compound. 149 alkane propane cycloalkane cyclopropane structure H H C H C C H H H 150 alkane propane cycloalkane cyclopropane structure H H C H C C H H H H butane cyclobutane H C H C H H C H C H H 151 152 153 154 155 Conformational possibilities for cyclohexane 156 157 158 Some substituents 159 Some substituents Substituent F Name fluoro 160 Some substituents Substituent F Cl Name fluoro chloro 161 Some substituents Substituent F Cl Br Name fluoro chloro bromo 162 Some substituents Substituent F Cl Br I Name fluoro chloro bromo iodo 163 Some substituents Substituent F Cl Br I Name fluoro chloro bromo iodo Note: the ending change ide chloride to chloro o as in 164 Name the following 165 H 1. H C F H Name the following 166 Name the following H 1. H C F H H H H C C F 2. H F 167 Name the following H 1. H C F H H H H C C F 2. H F H H H 3. H C C C F H F Cl 168 Name the following H 1. H C F H H H H C C F 2. H F H H H 3. H C C C F H F Cl H H Br H 4. H C C C C H H Br H Br 169 Name the following H 1. H C F H H H H C C F 2. H F H H H 3. H C C C F H F Cl H H Br H 4. H C C C C H H Br H Br fluoromethane 170 Name the following H 1. H C F H H H H C C F 2. H F H H H 3. H C C C F H F Cl H H Br H 4. H C C C C H H Br H Br fluoromethane 1,1-difluoroethane 171 Name the following H 1. H C F fluoromethane H H H H C C F 2. 1,1-difluoroethane H F H H H 3. 1-chloro-1,2-difluoropropane H C C C F H F Cl H H Br H 4. H C C C C H H Br H Br 172 Name the following H 1. H C F fluoromethane H H H H C C F 2. 1,1-difluoroethane H F H H H 3. 1-chloro-1,2-difluoropropane H C C C F H F Cl H H Br H 4. 1,2,3-tribromobutane H C C C C H H Br H Br 173 Name the following H 1. H C F fluoromethane H H H H C C F 2. 1,1-difluoroethane H F H H H 3. 1-chloro-1,2-difluoropropane* H C C C F H F Cl H H Br H 4. 1,2,3-tribromobutane* H C C C C H *(there is more than one form of this compound) H Br H Br 174 Some simple reactions of alkanes, alkenes, and alkynes 175 Some simple reactions of alkanes, alkenes, and alkynes Combustion: CH4 + 2 O2 CO2 + 2 H2O 176 Some simple reactions of alkanes, alkenes, and alkynes Combustion: CH4 + 2 O2 CO2 + 2 H2O When the products are CO2 and H2O it is termed a complete combustion. 177 Some simple reactions of alkanes, alkenes, and alkynes Combustion: CH4 + 2 O2 CO2 + 2 H2O When the products are CO2 and H2O it is termed a complete combustion. With insufficient O2, CO will be formed. E. g. 2 CH4 + 3 O2 2 CO + 4 H2O 178 Some simple reactions of alkanes, alkenes, and alkynes Combustion: CH4 + 2 O2 CO2 + 2 H2O When the products are CO2 and H2O it is termed a complete combustion. With insufficient O2, CO will be formed. E. g. 2 CH4 + 3 O2 2 CO + 4 H2O This is called an incomplete combustion. 179