10.1 Hydrocarbons 10.2 Aromatic Compounds 10.3 Functional Groups 10.4 Stereochemistry Chapter 10. Organic Chemistry - Structure Chemistry, 2nd Canadian

10.1 Hydrocarbons

10.2 Aromatic Compounds

10.3 Functional Groups

10.4 Stereochemistry

Chapter 10. Organic Chemistry - Structure

Chemistry, 2nd Canadian Edition ©2013 John Wiley & Sons Canada, Ltd.

10.1 Hydrocarbons

Learning objective:

Draw and naming hydrocarbons using the IUPAC system


10.1 Hydrocarbons

Alkanes

CnH2n+2

saturated (single C-C bonds only)

methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane


Alkanes


Alkane Isomers


IsobutaneButane

Pentane Isopentane Neopentane

Alkyl Groups


Naming Branched-Chain Alkanes


1. Locate the longest continuous chain of carbon atoms.2. Number the longest chain beginning with the end

nearest the substituent.3. Number the substituent groups accordingly.

Naming Branched-Chain Alkanes


Example 10 – 1 Naming Alkanes

Name the following alkanes:


Example 10 – 2 Drawing Alkanes

Draw line structures of the following alkanes: (a) 2,3,6-trimethyloctane; (b) 5-ethyl-2-methyl-5-propylnonane; and (c) 2-methylbutane.


Cycloalkanes


Common Substituents


Alkenes

CnH2n

Unsaturated (contain at least one C-C double bond)

ethene, propene, butene, …


Alkynes

CnH2n-2

Unsaturated (contain at least one C-C triple bond)

ethyne, propyne, butyne, …


Naming Alkenes and Alkynes


10.2 Aromatic Compounds

Learning objective:

Draw and name aromatic compounds using the IUPAC system


Structure of Benzene


Bonding in Benzene


Naming Benzene Compounds


Example 10-3 Naming Benzene Compounds

Name the following compounds:


10.3 Functional Groups

Learning objective:

Drawing and naming compounds containing common functional groups.


Functional Groups

Alkyl HalidesAlcohols

EthersAmines

AldehydesKetones

Carboxylic AcidsEsters

AmidesNitriles


Alkyl Halides


Example 10 – 4 Alkyl Halides

Draw line structures and give the IUPAC names for all of the structural isomers of C4H9Br. State whether each is a primary, secondary, or tertiary alkyl halide.


Alcohols


Alcohols H-bond, as does water

Primary Alcohols


Secondary Alcohols


Tertiary Alcohols


Naming Alcohols


Synthesizing Alcohols


o

2 3

400 C2 3ZnO/Cr O catalystCO 2H CH OH

Yeast6 12 6 2 5 2C H O 2C H OH 2CO

Acid3 2 2 CatalystCH CH = CH + H O CH3CH=CH2

OH

Propene Isopropanol

Example 10 – 5 Alcohols

Write line structures for each of the following, and state whether each is a primary, secondary, or tertiary alcohol:

(a) 3-pentanol; (b) 2-methyl-2-butanol; and (c) 1-hexanol.


Ethers


2 4H SO2R OH HO R R O R H O

2 4H SO3 2 3 2 2 3CH CH OH CH CH O CH CH

Example 10 – 6 Ethers

Write line structures for (a) diethyl ether, (b) ethyl propyl ether, and (c) ethyl isopropyl ether.


Amines


Amines


Example 10 – 7 Amines

Name the following amines and classify each as primary, secondary, or tertiary:


The Carbonyl Group

Appears in five common functional groups:Aldehydes, Ketones, Carboxylic Acids, Esters and Amides


Aldehydes and Ketones


Aldehydes and Ketones


Example 10 – 8 Aldehydes and Ketones

Give IUPAC names for the following compounds:


Carboxylic Acids


Carboxylic Acids


Carboxylic Acids


Esters


Amides


Example 10 – 9 Carboxylic Acids, Esters, and Amides

Draw the following compounds: (a) hexanoic acid; (b) 2-ethyl butanoic acid; (c) methyl propanoate, (d) phenyl ethanoate; (e) N-ethylethanamide (N-ethylacetamide); and (f) N-methyl-N-phenylpropanamide.


Nitriles


Functional Group Summary


Functional Group Summary – cont’d



Learning objective:

Recognizing, naming and drawing stereoisomers.




These are different molecules!


1. List the groups bound directly to the C=C double bond. In this case, they are –H, -Br, -Cl and –CH3.

2. Order them according to priority (higher molecular weight = higher priority) on each C atom. Here, Br > Cl and CH3 > H.

3. Look at the highest priority ones (Br, CH3). If they are cis to one another, it is Z. If they are trans, it is E. This one is therefore (E)-1-bromo-1-chloropropene

The E/Z System

Example 10 – 10 E/Z Stereoisomers

Draw and name the two stereoisomers of 1-bromo-3-chloro-4-isopropyl-3-heptene.


Learn to Draw in Three Dimensions!


Conformations


Drawing a Newman Projection


Example 10-11 Drawing Newman Projections


Example 10-12 Drawing a Line Structure from a Newman Projection


Potential Energy During a Rotation


Enantiomers

Your hands are enantiomers – non-superimposable mirror images of one another


Chirality

2-pentanol

These are therefore enantiomers!Chemistry, 2nd Canadian Edition ©2013 John Wiley & Sons Canada, Ltd.

Chirality


Example 10 – 13 Chiral Compounds

Two amino acids are glycine and leucine. Determine whether each of these compounds is chiral or achiral.


The R/S System for Naming Chiral Compounds

Chirality may determine the activity of a molecule!


The R/S System


1. Locate the chirality centre, identify the four groups attached to it, and assign priorities to them just as we did for the E/Z configurations of cis–trans stereoisomers.

2. Orient the molecule so that the group having the lowest priority is pointing away from you.

3. Read the other three groups (pointing toward you) from highest to lowest priority. If these are in a clockwise direction, the molecule is the R enantiomer. If they are in the counter-clockwise direction, it is the S enantiomer.

The R/S System


The groups attached to the chirality centre in increasing priority are - H, -CH3, -C6H4 and COOH. The other three groups from highest to lowest priority are - COOH, -C6H4 and -CH3.These three groups are in a clockwise order, and so this is the (R)-ibuprofen, and the active enantiomer must be (S)-ibuprofen.

The inactive enantiomer of Ibuprofen

Example 10 – 14 Identifying R and S Enantiomers

Assign an R or S configuration to the chirality centre in the enantiomer of 3,3-dimethylcyclohexanol shown:


Chapter 10 Visual Summary








Documents

10.1 Hydrocarbons 10.2 Aromatic Compounds 10.3 Functional Groups 10.4 Stereochemistry Chapter 10. Organic Chemistry - Structure Chemistry, 2nd Canadian