SAMPLE PROBLEM 13.1 Naming Alcohols Give the IUPAC name for the following: SOLUTION STEP 1 Name the longest carbon chain containing the —OH group. The parent chain is pentane; the alcohol is named pentanol. STEP 2 Number the longest chain starting at the end closer to the —OH group. The carbon chain is numbered to give the position of the —OH group as carbon 2 to give 2-pentanol. STEP 3 Name and number other substituents relative to the —OH group. With a methyl group on carbon 4, the compound is named 4-methyl-2pentanol. STUDY CHECK Give the IUPAC name for the following: Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.2 Thiols Draw the condensed structural formula of the following: a. 1-butanethiol b. cyclohexanethiol SOLUTION a. This compound has a —SH group on the first carbon of a butane chain: b. This compound has a —SH group on cyclohexane: STUDY CHECK What is the condensed structural formula of ethanethiol? Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.3 Ethers Give the IUPAC name for the following: SOLUTION STEP 1 Write the alkane name of the longer carbon chain: STEP 2 Name the oxygen and smaller alkyl group as a substituent called an alkoxy group: STEP 3 Number the longer carbon chain from the end nearer the alkoxy group and give its location. STUDY CHECK What is the common name of ethoxybenzene? Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.4 Isomers Draw the condensed structural formulas and give the IUPAC and common names of two alcohols and one ether with a molecular formula of C3H8O. SOLUTION To draw the condensed structural formulas for alcohols, the hydroxyl group is bonded to two different atoms in a chain of three carbon atoms. For the ether, two alkyl groups are bonded to an oxygen atom: STUDY CHECK Write the IUPAC names of the unbranched isomers of C4H10O. Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.5 Cyclic Ethers Identify the following as a cyclic alcohol, ether, or cyclic ether: SOLUTION a. A cyclic ether has an oxygen atom in the ring. b. A cyclic alcohol has a hydroxyl group bonded to a cycloalkane. c. An ether has an oxygen atom with single bonds to two carbon groups. STUDY CHECK What is the difference between furan and pyran? Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.6 Physical Properties of Alcohols, Ethers, and Phenols Predict which compound in each of the following pairs will be more soluble in water: a. butane or 1-propanol b. 1-propanol or 1-heptanol SOLUTION a. 1-Propanol is more soluble because it can form hydrogen bonds with water. b. The 1-propanol is more soluble because it has a shorter carbon chain. STUDY CHECK Dimethyl ether and ethanol both have molar masses of 46 g/mole. However, ethanol has a much higher boiling point than dimethyl ether. How would you explain this difference in boiling points? Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.7 Dehydration of Alcohols Draw the condensed structural formula of the alcohol that is needed to produce each of the following products: SOLUTION a. Because the molecule is a symmetrical alcohol, the —H may be removed from the either carbon adjacent to the carbon attached to the —OH group, which forms the following product: b. The —OH of this alcohol is removed along with a —H from an adjacent carbon. Remember that the hydrogen atoms are not drawn in this type of geometric formula: STUDY CHECK What is the name of the alkene produced by the dehydration of cyclopentanol? Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.8 Predicting Reactants Draw the condensed structural formula for the alkenes produced by the dehydration of the following alcohols: SOLUTION STUDY CHECK What is the name of an alcohol that forms 2-methylpropene? Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc. SAMPLE PROBLEM 13.9 Oxidation of Alcohols Draw the condensed structural formula of the aldehyde or ketone formed by the oxidation of each of the following: SOLUTION a. A secondary (2˚) alcohol oxidizes to a ketone: b. A primary (1˚) alcohol oxidizes to an aldehyde: STUDY CHECK Draw the condensed structural formula of the product formed by the oxidation of 2-propanol. Timberlake: General, Organic & Biological Chemistry Copyright ©2010 by Pearson Education, Inc.