Background for Alkenes, Alkynes, and Dienes
Alkenes contain carbon-carbon double bonds.  Alkynes contain carbon-carbon triple bonds.  Dienes contain more than one carbon-carbon double bond.  Alkenes, alkynes, and dienes are less dense than water, are nonpolar, and have boiling points and melting points similar to alkanes.  The carbon in an alkene is sp², has a bond angle of 120^o, and a trigonal planar shape.  A carbon-carbon double bond contains one sigma bond and one pi bond.  No rotation is possible around a carbon-carbon double bond.  The carbon in an alkyne is sp, has a bond angle of 180^o, and a linear shape.  A carbon-carbon triple bond contains one sigma bond and two pi bonds.  In dienes, allenes contains two double bonds that share a carbon. Conjugated dienes have double bonds that alternate with single bonds. Isolated dienes have double bonds that are separated by two or more single bonds.  In an unsubstituted alkene, no alkyl groups are attached to a carbon-carbon double bond.  In a monosubstituted alkene, one R group is attached to the carbon-carbon double bond. In a disubstituted alkene, two alkyl groups are attached to the carbon-carbon double bond. In a trisubstituted alkene, three alkyl groups are attached to the carbon-carbon double bond.  In a tetrasubstituted alkene, four alkyl groups are attached to the carbon-carbon double bond.  A terminal alkyne contains at least one hydrogen attached to the carbon-carbon triple bond.  An alkyne that is not terminal contains two alkyl groups attached to the carbon-carbon triple bond.

Nomenclature of Alkenes, Alkynes, and Dienes
Circle the longest continuous carbon chain as the parent compound.  Use Aene@ for alkene, and Ayne@ for alkyne.   Number from whichever end that gives the lowest possible number for the multiple bonds.  Name and number substituents. If both a double bond and a triple bond are present, number from whichever end that gives the lowest possible number for the multiple bonds. If the double bond and a triple bond are equal distance, then the double bond has priority over the triple bond.  Name compounds with a double bond and a triple bond as enyne, giving positions of the multiple bonds.  OH has priority over double and triple bonds. Cis has the same group on the same side.  Trans has the same group on opposite sides.  In the Cahn-Ingold-Prelog rules, Z has the highest ranking group on the same side and E has the highest ranking group on opposite sides.  Rank the first atoms directly attached to the carbon-carbon double bond.  The atom with the highest atomic number has the highest ranking. If the priority cannot be determined by Rule 1, then compare the next group of atoms. Double bonds are duplicated and triple bonds are triplicated, with imaginary atoms.

Synthesis of Alkenes
Alkyl halides are dehydrohalogenated with base to form alkenes.  Alcohols are dehydrated with heat and acid to form alkenes. The product with the most number of carbons attached to the carbon-carbon double bond is formed in the higher yield.

Synthesis of Alkynes
Vicinal dihalides are dehydrohalogenated twice with base to form alkynes. Geminal dihalides are dehydrohalogenated twice with base to form alkynes.

Reactions of Alkenes
In Markovnikov addition, H of HZ adds to carbon with most hydrogens directly attached; the more stable carbocation intermediate is formed.  In anti addition, the groups add on opposite sides of the double bond.  In syn addition, the groups add on the same side of the double bond.  A regioselective reaction is a reaction in which one of two possible isomers predominates.  A regiospecific reaction is a reaction in which one of two possible isomers is formed exclusively.  An hydrogen halide adds across a double bond to form an alkyl halide, via Markovnikov addition. Halogen adds across a double bond to form a dihalolalkane, with anti addition. Water adds across a double bond to produce an alcohol, via Markovnikov addition. Hydrogen adds across a double bond, via syn addition, to form an alkane.

Reactions of Alkynes
Hydrogen halide adds across a triple bond, via Markovnikov addition and with anti or syn addition, to form dihaloalkanes. Halogen adds across a triple bond to form a tetrahaloalkane.  Hydrogen adds across a triple bond to make an alkane.

Polymers of Alkenes
Ethylene is polymerized to polyethylene, which is used for bags, films, and bottles. Propylene is polymerized to polypropylene, which is used for plastics.  Styrene is polymerized to polystyrene, which is used for plastics, plastic cups, and foam insulation.  Methyl α-methacrylate is polymerized to polymethyl α-methacrylate, which is used for plexiglass and Lucite paints.  Acrylonitrile is polymerized to polyacrylonitrile, which is used as Orlon or Acrylan fibers.  Tetrafluoroethylene is polymerized to polytetrafluoroethylene, which is used as Teflon.  Vinyl chloride is polymerized to polyvinyl chloride, which is used in plastics, films, and plumbing. Vinylidene chloride is polymerized to polyvinylidene chloride, which is used in Saran.

Oxidation Reactions of Alkenes and Alkynes
Potassium permanganate oxidizes alkenes to diols, with syn addition. Ozone oxidizes alkenes to aldehydes and / or ketones. Potassium permanganate oxidizes alkenes to diketones. Ozone oxidizes alkynes to carboxylic acids.

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Background information for alkenes, alkynes, and dienes are described in terms of definitions, properties, uses, structures, and classification.  The rules for the IUPAC nomenclature of alkenes, alkynes, and dienes are discussed.  Alkenes are additionally named using cis and trans or E and Z.  Alkenes are synthesized by the dehalogenation of alkyl halides and the dehydration of alcohols.  Alkynes are synthesized by the dehydrohalogenation of vicinal and geminal dihalides.  Alkyl halides are formed by the reaction of alkenes with hydrogen halides.  Alkenes are halogenated to give dihaloalkanes.  Alkenes are hydrated to give alcohols.  Reduction of alkenes give alkanes.  Alkynes react with hydrogen halides to give dihaloalkanes or with halogens to give tetrahaloalkanes.  Hydrogenation of alkynes give alkanes.  Alkenes are polymerized.  Alkenes are oxidized to diols with potassium permanganate or to aldehydes and / or ketones with ozone.  Alkynes are oxidized to diketones with potassium permanganate or to carboxylic acids with ozone.

This tutorial provides the comprehensive coverage of the chapter with easy introduction and simple illustration. It features:

• Concept map showing interconnections of new concepts in this tutorial and those previously introduced.
• Definition slides introduce terms as they are needed.
• Visual representation of concepts.
• Use of colors to emphasis points.
• Outline of chemical properties, uses, structures, and classification.
• Easy-to-follow animations of stated rules of nomenclature.
• Detailed stepwise explanations and animations of reactions and mechanisms.
• Examples worked out step-by-step throughout the tutorial.
• A concise summary is given at the conclusion of the tutorial.

Background Information for Alkenes, Alkynes, and Dienes

• Definitions
• Properties
• Uses
• Structure
• Classification

Nomenclature of Alkenes, Alkynes, and Dienes

• IUPAC
• Cis and Trans
• E and Z

Synthesis of Alkenes

• Dehalogenation of Alkyl Halides
• Dehydration of Alcohols
• Products of Elimination Reactions

Synthesis of Alkynes

• Dehydrohalogenation of Vicinal Dihalides
• Dehydrohalogenation of Geminal Dihalides

Reactions of Alkenes

• Definitions
• Addition of Hydrogen Halides
• Halogenation
• Hydration
• Hydrogenation

Reactions of Alkynes

• Addition of Hydrogen Halides
• Halogenation
• Hydrogenation

Polymerization of Alkenes

• Definitions
• Examples

Oxidation of Alkenes and Alkynes

• Potassium Permanganate Oxidation
• Ozonolysis