Chapter 8 Introduction to Alkyl Halides Alcohols Ethers
- Slides: 31
Chapter 8 Introduction to Alkyl Halides, Alcohols, Ethers, Thiols, and Sulfides
Alkyl Halides • Organic compounds containing at least one carbon-halogen bond (C-X) – X = F, Cl, Br, or I – X replaces an H • Properties and some uses – Fire-resistant solvents – Refrigerants – Pharmaceuticals and precursors 2
Nomenclature • Two systems: 1) Common 2) IUPAC 3
Common Naming Rules • Generally used only for simple compounds 1) Identify the alkyl group and name it as a substituent • change the ending from “-ane” to “-yl, ” if applicable 2) Identify the halide and name it 3) Leave a space between the two names from steps 1 and 2. 4
Alkyl Halides • Other common names to learn: 8. 1 Nomenclature 5
IUPAC Naming Rules 1) Identify the longest carbon chain and name it as the parent • Contains double or triple bond if present 2) Number the parent chain beginning at the end nearest any substituent (alkyl or halogen) 3) If more than one of the same kind of substituent is present, number each and use the Greek prefixes to indicate how many 6
4) If different substituents are equidistant from the ends of the parent chain, begin at the end nearer the substituent whose name comes first in the alphabet. 7
Problems • Name the following alkyl halides using common nomenclature • Name the following alkyl halides using IUPAC nomenclature: 8
Problems 1) CHCl 3 is commonly known as chloroform. What is its IUPAC name? 2) Based on what you know from question #1, what are the common and IUPAC names for CHBr 3, CHI 3, and CHF 3?
General Classifications • Alkyl halides can be classifed as methyl, primary, secondary, or tertiary based on the number of organic groups bonded to the halogen bearing carbon 8. 1 Nomenclature 10
Problem • Draw 4 -chloro-3, 4 -dimethyl-1 -octene. Classify this alkyl halide based on degree of substitution. 11
Alcohols • Contain an OH group connected to a saturated (sp 3 -hybridized) Carbon – Important solvents and synthesis intermediates – Methanol (Methyl Alcohol) • Common solvent • Fuel additive – Ethanol (Ethyl Alcohol) • Solvent • Fuel • Beverage – Isopropanol (Isopropyl Alcohol) • Rubbing alcohol • Solvent • Disinfectant 12
Phenols • Compounds containing an OH group bonded to a carbon in a benzene ring • Building polycarbonates, epoxies, Bakelite, nylon, detergents and a large collection of drugs, herbicides and pharmaceuticals. BPA Eugenol 13
Glycols • Compounds containing two or more hyrodoxyl (-OH) groups – Diol: contains two –OH groups • Geminal: OH’s are on the same carbon • Vicinal: OH’s are on adjacent carbons • General: OH’s located in non-geminal/nonvicinal positions Ethylene Glycol Resorcinol 14
General Classification 15
Nomenclature • Two types: – Common – IUPAC 16
Common Naming Rules • Used for simple and common alcohols 1) Identify the alkyl group to which the hydroxyl group is attached and name this as a substituent • Ethane Ethyl 2) Add the word “Alcohol” 17
IUPAC Naming Rules 1) Select the longest carbon chain containing the hydroxyl group, and derive the parent name by replacing the “-e” ending of the corresponding alkane with “-ol “ 2) Number the chain from the end nearest to the hydroxyl group 3) Number substituents according to position on chain and then list them in alphabetical order as usual 2 -chloro-5 -methyl-1 -hexanol Or 2 -chloro-5 -methylhexan-1 -ol 18
4) If there are more than one hydroxyl groups, use Greek prefixes to indicate how many 1. Do not drop the final e of the alkane 5) If stereochemistry is known, indicate it
Naming Phenols 1) Use “phenol” (the French name for benzene) as the parent hydrocarbon name, not benzene 2) Name substituents on aromatic ring by their position from OH 20
Problems 1) Name the following molecules: 2) Classify the first two molecules above based on level of substitution (1°, 2°, 3° alcohol) 3) Draw the following molecules – – 1, 2, 3 -propanetriol 2 -ethyl-3 -methylphenol 21
Thiols • Compounds that contain a carbon bonded to a sulfhydryl group (-SH) • Sulfur analogs of alcohols • R-SH vs. R-OH Ethanethiol vs. Ethanol • Stinky molecules • Also known as “Mercaptans” • The –SH group is also called a “mercapto” group 22
Nomenclature of Thiols • Common: – Named in the same fashion as alcohols • The word mercaptan replaces alcohol in the name of the equivalent alcohol compound – Example: CH 3 SH would be methyl mercaptan, just as CH 3 OH is called methyl alcohol. Methyl mercaptan Methyl Alcohol
• IUPAC 1) Identify the longest carbon chain containing the sulfhydryl group. Name this chain and add “thiol” to the end (no space). 2) Number the chain so that the carbon connected to the –SH group has the lowest number possible 3) Name and number all of the substituents and place them, in alphabetical order, in front of the parent chain name. 2 -hexanethiol 2 -ethyl-1 -hexanethiol
Problems • Name the following compounds: • Draw: – 3, 3 -dimethyl-1 -butanethiol – 2 -ethylcyclohexanethiol – Trans-3 -heptene-2 -thiol 25
Hmmmmm….
Principle Group and Principle Chain • Principle Group: the functional group upon which the name of a molecule is based • Cited as the suffix in the name • Example: Pentanol • Have priorities in a molecule • All other substituents are cited as prefixes (except multiple bonds) • Carboxylic acid > anhydride > ester > acid halide > amide > nitrile > aldehyde > ketone > alcohol/phenol > thiol > amine 8. 1 Nomenclature 27
1) Identify the principle group (e. g. , -OH > -SH) 2) Identify the principle chain 1. The carbon chain on which is the name is based • Priorities for picking the principle chain: a) The carbon chain with the greatest number of principle groups b) The carbon chain with the greatest number of double and triple bonds c) Of greatest length d) With the greatest number of other substituents
Principle Group and Principle Chain 3) Number the carbons of the principle chain giving the lowest numbers: a) b) c) d) For the principle groups For multiple bonds (C=C > C C) For other substituents For the substituent cited first in the name 8. 1 Nomenclature 29
Principle Group and Principle Chain 4) Begin construction of the name with the name of the hydrocarbon corresponding to the principle chain a) Cite principle group by suffix and number 1. Will be last number in molecular name b) If there is no principle group, name the compound as a substituted hydrocarbon c) Cite the names and numbers of other substituents in alphabetical order 8. 1 Nomenclature 30
Problems • Name the following compounds:
- Hydrogen halide
- Alcohols phenols thiols and ethers
- Nucleophilic substitution of alkyl halides
- Elimination reaction
- Nucleophilicity trend
- Alcohols nomenclature
- Nucleophilic substitution of alkyl halides
- Alkyl halide examples
- Ch3omgbr name
- Alkyl halide reactions
- Alkyl examples
- Properties of alkyl halides
- Ester naamgeving
- Naming esters
- Ether cleavage
- Naming ethers
- Ethers naming
- Ethers boiling point
- Nomenclature of ethers
- Acidic cleavage of ethers
- Greenyar
- Acidic cleavage of ethers
- Grignard reagent formula
- Cppp nucleus
- What is secondary alcohol
- Secondary alcohol oxidation
- Ester + lialh4
- Lucas test for alcohols
- Chemsheets reactions of alcohols 1 answers
- Na2cr2o7 h2so4
- Sp
- Names of sugar alcohols