Organic Chemistry

Chapter 10 Introduction to Organic Chemistry: Alkanes 10.3 Alkanes with Substituents 1 Isomers of Butane Isomers have the same molecular formula. have different atom arrangements. of butane (C4H10) are a straight chain and a branched chain. 2

Alkyl groups Alkyl groups are alkanes that are missing one H. substituents attached to carbon chains. named with a yl ending. H H H C CH3 H H

H C C H H CH3 methyl CH2 ethyl

3 Naming Substituents TABLE 10.6 In the IUPAC system, a carbon branch is named as an alkyl group. halogen atoms are named as halo. 4 Alkanes with Substituents CH3 CH3 CH

CH3 methylpropane methyl groups CH3 CH3 CH3 CH CH2 CH CH3 2,4-dimethylpentane 5 Naming Alkanes Give the name of

STEP 1 CH 3 CH3 CH3CHCHCH3 Name the longest continuous chain. CH3 CH3 CH3CHCHCH3 butane 6 Naming Alkanes Give the name of

STEP 2 CH 3 CH3 CH3CHCHCH3 Number chain. CH3 CH3 CH3CHCHCH3 1 2 3 4 STEP 3 Locate substituents and name. 2,3-dimethylbutane

7 Learning Check Write the name of Cl CH3 CH3CH2CHCHCH3 8 Solution STEP 1 Longest chain is pentane. STEP 2

Number chain from end nearest substituent. Cl CH3 CH3CH2CHCHCH3 5 4 3 2 1 STEP 3 Locate substituents and name alphabetically. 3-chloro-2-methylpentane 9 Learning Check Give the IUPAC name for each of the following:

A. CH3 CH3 | | CH3CHCH2 CHCH3 B. Cl CH3 | | CH3CH2CHCH2CCH2CH3 | Cl

10 Solution A. CH3 CH3 | | CH3CHCH2 CHCH3 1 B. 2 3

4 2,4-dimethylpentane 5 Cl CH3 more substituents = C3 | | CH3CH2CHCH2CCH2CH3 | Cl 7 6 5

4 3 2 1 3,5-dichloro-3-methylheptane 11 Learning Check Draw the condensed structural formula for 2-bromo-4-chlorobutane. 12

Solution 2-bromo-4-chlorobutane STEP 1 Longest chain has 4 carbon atoms. CCCC STEP 2 Number chain and add substituents. Br C C C C Cl 1 2 3 4 STEP 3 Add hydrogen to complete 4 bonds to each C. Br CH3CHCH2CH2Cl 13 Naming Cycloalkanes with

Substituents The name of a substituent is placed in front of the cycloalkane name. methylcyclobutane chlorocyclopentane CH3 Cl 14 Learning Check Name each of the following. 1. CH3

CH2CH3 2. 15 Solution Name each of the following. 1. methylcyclopropane 2. ethylcyclohexane 16