Organic Chemistry ! ! !. Alkanes Simplest organic compounds - ane ending Hydrocarbons Compounds made...

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Transcript of Organic Chemistry ! ! !. Alkanes Simplest organic compounds - ane ending Hydrocarbons Compounds made...

Organic Chemistry ! ! !

Alkanes

Simplest organic compounds

- ane ending

HydrocarbonsCompounds made of only hydrogen and carbon atoms

Saturated vs. unsaturated

General formula pattern (CnH2n + 2)

Ex. Methane (CH4) and propane (CH3)

Hydrocarbons

Carbon atom—up to 4 bonds

Hydrogen atom—forms 1 bond

Carbon and hydrogen bonds can form chains, branches, or ring structures

Ex. Glucose, amino acid, octane

IsomersChemical compounds with the SAME molecular formula but DIFFERENT structure/arrangement

Different compounds

Many molecular formulas have several different structural arrangements.

Few—assign prefixes

Many—use systematic naming system

Functional Groups

Atom/groups of atoms hanging off a hydrocarbon chain or ring structure

Gives chemical compound its unique properties, part of compound participating in chemical reaction.

Compounds with same functional group—similar chemical properties.

1. Alkyl Group

Hydrocarbon branch hanging off a carbon chain or ring

Originally an alkane, one hydrogen atom removed

Cyclo—compounds with ring structure

Ex. 1 Methane (CH4)— Methyl (--CH3)

Ex. 2 Ethane (CH3CH3)— Ethyl (--CH2CH3)

2. Alcohols

Identified by the presence of a hydroxyl group(--OH)

Hydrocarbon with an –OH hanging off

Can have more than one hydroxyl group

General formula: R—OHR = hydrocarbon

Ex. 1 methane --- methanol (CH3OH)

Ex. 2 ethane --- ethanol (CH3CH2OH)

3. Carboxylic Acids

Identified by the presence of a carboxyl group (--COOH)

Gives acidic properties to organic compounds

Generic formula: R—COOH

Ex. 1 Methanoic acid/formic acid

Ex. 2 Ethanoic acid/acetic acid

Organic Nomenclature

Nomenclature 1) Find the longest continuous chain—(carbon backbone)

• Stem name = identity of carbon backbone.

2) Number carbons so the functional groups are at the lowest carbon, want lowest possible numbering.

-prefixes indicate functional groups hanging off backbone

3) Double and triple bonds trump functional groups in naming with lowest possible numbering.

4) Use di-, tri-, tetra- , etc. for identical groups on carbon backbone. List position with number even if on the same carbon.

5) List groups in alphabetical order

Ex. 1

Ex. 2

Alkenes

Contain double bonds to carbon

--ene ending

Alkynes

Contain triple bonds to carbon

--yne ending

Ex. 4 3-heptyne

Ex. 5 3-methyldecane

Ex. 6 2-chloro-3-octene

Draw carbon skeleton first

Numbers indicate where functional groups and bonds are located.

Homework

Read pp. 59-64, A22-A25

Complete Organic Nomenclature worksheet