Organic Chemistry I

The study of carbon-containing compounds

Unit 1

A little bit of everything…

Oops!

We are not starting at the beginning of Chapter 1… because you need a little more time

with the concepts from the following sections:

2.12, 1.10, 1.11, 2.13, 2.14

Hydrocarbons

Compounds that contain only H and C atoms. alkanes (contain all single bonds) alkenes (contain C=C) alkynes (contain C≡C) aromatics (contain a benzene ring)

Alkanes

Each C atom is bonded to 4 other atoms...why?

methane CH4

ethane CH3CH3

propane CH3CH2CH3

butane CH3(CH2)2CH3

pentane CH3(CH2)3CH3

hexane CH3(CH2)4CH3

heptane CH3(CH2)5CH3

octane CH3(CH2)6CH3

nonane CH3(CH2)7CH3

decane CH3(CH2)8CH3

Alkanes

The most significant reaction of alkanes is combustion. This is because alkanes do not have

any functional groups. Functional groups are where

reactions occur.

CH3(CH2)8CH3 + 15.5 O2(g) 10CO2(g) + 11H2O(l)

Showing the Structure of an Organic Molecule

You must be able to read and interpret drawings of molecules from the start!

structural formula = Lewis structure condensed (structural) formula line-angle formula 3-dimensional formula (The molecular formula does not show

structure. It just gives numbers and types of atoms.)

Molecular Formula, Lewis Structure, and Condensed Structural Formula

These are all the same compound: cis-hex-3-en-2-one

The Lewis structure shows all bonds and unbonded

valence electrons. Please view the Lewis structures

PowerPoint on the 2114 web page if you need a refresher.

Condensed Structural Formula

• The atoms following the C are bonded to the C: CHCl2CH3

• Sometimes the atoms bonded to the leading C are shown on the left:

H3CCH2CH3 or CH3CH2CH3

• The C is bonded to the C immediately before it and the C atom immediately after it…all C atoms in molecules have 4 bonds.

Condensed Structural Formula

• A group bonded to a C is shown in parentheses, except on the last C.

• Typically, C=C and C≡C are shown, but C=O is not.

CH3CH2CH=CHCOCH3

CH3CH2CH2OH is 1-propanol CH3CH(OH)CH3 is 2-propanol

Line-Angle Structure

There is a C at the end of every line segment and enough H atoms to give

each neutral C four bonds.

3-D Structure

Solid lines are bonds in the plane of the board or paper.

Wedges show bonds to atoms in front of the plane.

Dashed lines show bonds to atoms behind the plane.

Showing the Structure of an Organic Molecule

START NOW practicing drawing these different types of structures!

Functional Groups

Is this compound an alkane?

Is it a hydrocarbon?

It contains two functional groups: an alkene and a ketone.

Functional groups are sites of reactivity in an organic compound.

Functional Groups

In hydrocarbons alkanes (no functional groups) alkenes (contain C=C) alkynes (contain C≡C) aromatics (contain an aromatic ring,

the most common of which is the benzene ring)

Two representations of a benzene ring…it is NOT classified as an alkene!

Functional Groups

In hydrocarbons

Alkyl Substituents We look for the longest chain of C

atoms in the molecule. Groups of atoms attached to the

C atoms in the chain are called substituents.

Alkyl Substituents

When the substituent is an alkane, it is called an alkyl group.

The letter R is often used to denote an alkyl substituent.

a methyl groupany alkyl group

Functional Groups In compounds containing O

alcohols (R-OH) ethers (R-O-R’) ketones (contain C=O) aldehydes (contain HC=O) carboxylic acids (COOH) carboxylic acid derivatives

esters (RCOOR’) amides (RCONH2, RCONHR’, RCONR’R”) acid chlorides (RCOCl)

Functional Groups

In compounds containing N amines (RNH2, RNHR’, RNR’R”)

amides (RCONH2, RCONHR’, RCONR’R”)

nitriles (R-C≡N) In compounds containing X

alkyl halides or haloalkanes X=halogen

Functional Groups-Alcohols (R-OH) and Ethers (R-O-R’)

Functional Groups-Aldehydes (HC=O) and Ketones (RC=OR’)

C=O is a carbonyl group.

C=O on the end of the carbon chain is an aldehyde.

C=O elswhere in the carbon chain is a ketone.

Functional Groups-Carboxylic Acids and Their Derivatives

COOH is a carboxylic acid group. COOR is an ester. COCl is an acid chloride.

Functional Groups-Amines, Amides, and Nitriles

Amides are like amines, but with an adjacent C=O.

Be careful! Both amines and amides have different forms: primary (1°), secondary (2°), and tertiary (3°).

Nitriles are R-CN.

Primary (1°) Amines and Amides

A primary (1°) amine has one C atom (one alkyl group R) and two H atoms bonded to the N. The general formula is RNH2.

A 1° amide has one acyl group and two H atoms bonded to the N. The general formula is RCONH2.

Secondary (2°) Amines and Amides

A secondary (2°) amine has two C atoms (two alkyl groups) and one H atom bonded to the N. The general formula is RNHR’.

A 2° amide has two C atoms (one in the acyl group) and one H atom bonded to the N. The general formula is RCONHR’.

Tertiary (3°) Amines and Amides

A tertiary (3°) amine has three C atoms (three alkyl groups) and no H atoms bonded to the N. The general formula is RNR’R”.

A 3° amide has three C atoms (one in the acyl group) and no H atoms bonded to the N. The general formula is RCONR’R”.

1°, 2°, 3° Amines and Amides

Classify these.

Functional Groups - Alkyl Halides

Cycloalkanes are alkanes

that have a ring of C atoms.

Classify the halides as 1°, 2°, or 3°.

Functional GroupsCircle and label each functional group.

fructose

acetaminophen

threonine

γ-butyrolactone (GBL)

vitamin A (retinol)