In organic chemistry, an alkane, or paraffin (a historical name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon-carbon bonds are single.[1] Alkanes have the general chemical formula CnH2n+2. The alkanes range in complexity from the simplest case of methane, CH4 where n = 1 (sometimes called the parent molecule), to arbitrarily large molecules.

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Alkanelecture,
IUPAC Nomenclature of Organic Compounds
*Introduction
The purpose of the IUPAC system of nomenclature is to establish an international
standard of naming compounds to facilitate communication. The goal of the system
is to give each structure
a unique and unambiguous name, and to correlate each name with a unique and
unambiguous structure.
I. Fundamental Principle
IUPAC nomenclature is based on naming a molecule’s longest chain of carbons
connected by single bonds, whether in a continuous chain or in a ring. All
deviations, either multiple bonds or atoms other than carbon and hydrogen, are
indicated by prefixes or suffixes accordin0g to a specific set of priorities.
II. Rules of Alkanes Nomenclature
Alkanes are the family of saturated hydrocarbons, that is, molecules containing carbon and
hydrogen connected by single bonds only. These molecules can be in continuous chains
(called linear or acyclic), or in rings (called cyclic or alicyclic).
The names of alkanes and cycloalkanes are the root names of organic compounds.

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1. Find the longest continuous carbon chain. Determine the root name for this parent
chain.
2. Number the chain in the direction such that the position number of the first substituent
is the smaller number. If the first substituents from either end have the same number, then
number so that the second substituent has the smaller number, etc.
3. Determine the name and position number of each substituent.
4. Indicate the number of identical groups by the prefixes di, tri, tetra, etc.
5. Place the position numbers and names of the substituent groups, in alphabetical order,
before the root name. In alphabetizing, ignore prefixes like sec-, tert-, di, tri, etc., but
include iso and cyclo. Always include a position number for each substituent, regardless of
redundancies.
-Example;
- Common branched substituents;

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-Additional Examples; Notice the applied rules:
-After the halogens, the substituents are arranged in alphabetical order;

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*Provide IUPAC Nomenclature of the following compounds:
Classification of Carbon
1. Primary carbons, are carbons attached to one other carbon. (Hydrogens – although
usually 3 in number in this case).
2. Secondary carbons are attached to two other carbons.
3. Tertiary carbons are attached to three other carbons.
4. Finally, quaternary carbons are attached to four other carbons.

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Physical Properties of Alkanes
* 1c to 5c are gases.
* 6c to 10c are liquids.
* more than 11c are semisolid.
* low melting point compared to more polar compounds:
-Increasing strength of intermolecular forces → Increasing melting point.
-Melting point increase as the number of carbons increase because of increase of surface
area.
-Increase of symmetry → Increase of melting point.
* Increase surface area → Increase of packing → Increase boiling point.
* Increasing branching → Longer distance between molecules → Low boiling point.
*Drastic Conditions are needed for the Rx. of alkane due to the 𝝈 bond strength which
make Alkanes less reactive and most of them nonreactive.
*Solubility
In water: In solvent:
-Almost totally insoluble in water. -Normally dissolve in solvent of low
-Low polarity and unable to form H-bonds. Polarity as benzene, 𝑪𝑪𝒍 𝟒 & other
hydrocarbon.
Reactions of Alkane
1. Combustion of alkane
*The Rx. is Exothermic !!!
-Complete Combustion; -Incomplete Combustion;
𝑪 𝟒 𝑯 𝟏𝟎 +
𝟏𝟑
𝟐
𝑶 𝟐 → 𝟒𝑪𝑶 𝟐 + 𝟓𝑯 𝟐 𝑶 𝑪 𝟒 𝑯 𝟏𝟎 +
𝟗
𝟐
𝑶 𝟐 → 4CO + 𝟓𝑯 𝟐 𝑶
Rx. causes pollution.
2. Oxidation Rx. of alkane

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3. Halogenation of alkane
*Chain Radical Rx.-a substitution Rx.
Chlorination of Methane Mechanism;
Bromination of Ethane Mechanism;
The same sequence:

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*Regeoselectivity:
𝑭 𝟐 > 𝑪𝒍 𝟐 > 𝑩𝒓 𝟐 > 𝑰 𝟐
𝑻𝒉𝒆 𝒎𝒐𝒔𝒕 𝑹𝒆𝒂𝒄𝒕𝒊𝒗𝒆 𝑹𝒆𝒂𝒄𝒕𝒊𝒗𝒆 𝒘𝒊𝒕𝒉 ONLY 𝑹 𝑰𝒏𝒆𝒓𝒕
(𝑬𝒙𝒑𝒍𝒐𝒔𝒊𝒗𝒆) 𝟑 𝒐
. 𝟐 𝒐
&𝟏 𝒐
𝒘𝒊𝒕𝒉 ↑ 𝒔𝒕𝒂𝒃𝒍 Rx. indirect
𝑹𝒙 𝒊𝒏𝒅𝒊𝒓𝒆𝒄𝒕 Radical R-Br(𝑲𝑰)𝑹 − 𝑰
𝑹 − 𝒄𝒍 (
𝑯𝑭
𝑺𝒃𝑭 𝟓
) 𝑹 − 𝑭
-Radical Stability;
Radicals are stabilized by conjugating, electron-withdrawing, and electron-donating groups
-Chlorination of Alkane:

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- Bromination of alkanes is more selective
The following reaction yields tert-butyl bromide with less than 1% of the primary isomer.
*Preparation of Alkene
1. Reduction of Alkene& Alkyne; Catalytic Reduction
2. From Alkyl halide
a. Via Reduc. Rx.
b. Via Grignard Reagent
*Grignard Reagent: (RMGX)

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c. Via Corey-House (Gilman reagent)
*C-C Coupling Rx.
d. Via Wurtz Rx.
*C-C Coupling Rx.
*Ascending Rx.
3. From Carboxylic acid
a. Using reducing agent
b. Via Decarboxylation (Using Sodalime)
c. Via Kolb's electrolytes
4. From Aldehydes& Ketones
a. Clemmensen's Reduction; for Ketones or aldehydes

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