9.3 Synthesis of Alkynes
Course Menu
- 8.0 Naming Alkenes
- 8.1 Introduction to Alkene Addition Reactions
- 8.2 Hydrohalogenation
- 8.3 Hydration of Alkenes
- 8.4 Addition of Alcohols
- 8.5 Catalytic Hydrogenation
- 8.6 Halogenation of Alkenes and Halohydrin Formation
- 8.7 Epoxidation, Anti Dihydroxylation, and Syn Dihydroxylation
- 8.8 Predicting the Products of Alkene Addition Reactions
- 8.9 Oxidative Cleavage Ozonolysis and Permanganate Cleavage
- 13.1 Naming Ethers
- 13.2 Synthesis of Ethers
- 13.3 Reactions of Ethers
- 13.4 Nomenclature of Epoxides
- 13.5 Synthesis of Epoxides
- 13.6 Ring Opening of Epoxides
- 13.7 Nomenclature, Synthesis, and Reactions of Thiols
- 13.8 Nomenclature, Synthesis, and Reactions of Sulfides
- 13.9 Organic Synthesis with Ethers and Epoxides
- 14.1 Introduction to IR Spectroscopy
- 14.2a IR Spectra of Carbonyl Compounds
- 14.2b The Effect of Conjugation on the Carbonyl Stretching Frequency
- 14.3 Interpreting More IR Spectra
- 14.4 Introduction to Mass Spectrometry
- 14.5 Isotope Effects in Mass Spectrometry
- 14.6a Fragmentation Patterns of Alkanes, Alkenes, and Aromatic Compounds
- 14.6b Fragmentation Patterns of Alkyl Halides, Alcohols, and Amines
- 14.6c Fragmentation Patterns of Ketones and Aldehydes
- 15.1 Introduction to NMR
- 15.2 The Number of Signals in C 13 NMR
- 15.3 The Number of Signals in Proton NMR
- 15.4 Homotopic vs Enantiotopic vs Diastereotopic
- 15.5a The Chemical Shift in C 13 and Proton NMR
- 15.5b The Integration or Area Under a Signal in Proton NMR
- 15.5c The Splitting or Multiplicity in Proton NMR
- 15.6a Interpreting NMR Example 1
- 15.6b Interpreting NMR Example 2
- 15.6c Interpreting NMR Example 3
- 15.6d Structural Determination From All Spectra Example 4
- 15.6e Structural Determination From All Spectra Example 5
- 15.7 Complex Splitting
- 16.1 Introduction to Conjugated Systems and Heats of Hydrogenation
- 16.2a Pi Molecular Orbitals 1,3 Butadiene
- 16.2b Pi Molecular Orbitals the Allyl System
- 16.2c Pi Molecular Orbitals 1,3,5 Hexatriene
- 16.3 UV Vis Spectroscopy
- 16.4 Electrophilic Addition to Conjugated Dienes
- 16.5 Diels Alder Reactions
- 16.6 Cycloaddition Reactions
- 16.7 Electrocyclic Reactions
- 16.8 Sigmatropic Rearrangements
- 18.1 Electrophilic Aromatic Substitution
- 18.2 Friedel Crafts Alkylation and Acylation
- 18.3 Activating and Deactivating Groups | Ortho/Para vs Meta Directors
- 18.4 Catalytic Hydrogenation and the Birch Reduction
- 18.5 Side-Chain Reactions of Benzenes
- 18.6 Nucleophilic Aromatic Substitution
- 18.7 Retrosynthesis with Aromatic Compounds
- 19.1 Nomenclature of Ketones and Aldehydes
- 19.2 Synthesis of Ketones and Aldehydes
- 19.3 Introduction to Nucleophilic Addition Reactions of Ketones and Aldehydes
- 19.4a Formation of Hemiacetals and Acetals (Addition of Alcohols)
- 19.4b Cyclic Acetals as Protecting Groups
- 19.5 Formation of Imines and Enamines (Addition of Amines)
- 19.6 Reduction of Aldehydes and Ketones
- 19.7a Addition of Carbon Nucleophiles (Acetylide Ions, Grignard Reagents,etc.)
- 19.7b The Wittig Reaction
- 19.8 Baeyer Villiger Oxidation
- 19.9 Retrosynthesis with Aldehydes and Ketones
- 20.1 Naming Carboxylic Acids and Carboxylic Acid Derivatives
- 20.2 Nucleophilic Acyl Substitution
- 20.3 The Mechanisms of Nucleophilic Acyl Substitution
- 20.4 Reaction with Organometallic Reagents
- 20.5 Hydride Reduction Reactions
- 20.6 Synthesis and Reactions of Acid Halides
- 20.7 Synthesis and Reactions of Acid Anhydrides
- 20.8 Synthesis and Reactions of Esters
- 20.9 Properties, Synthesis, and Reactions of Carboxylic Acids
- 20.10 Synthesis and Reactions of Amides
- 20.11 Synthesis and Reactions of Nitriles
- 20.12 Retrosynthesis with Carboxylic Acids / Acid Derivatives
- 21.1 Acidity of the Alpha Hydrogen
- 21.2 Mechanisms of Alpha Substitution Reactions
- 21.3 Alpha Halogenation
- 21.4 Alpha Alkylation (including the Stork Reaction)
- 21.5 Aldol Reactions
- 21.6 Claisen Condensation Reactions
- 21.7 The Malonic Ester Synthesis and the Acetoacetic Ester Synthesis
- 21.8 Michael Reactions
- 21.9 The Robinson Annulation
- 21.10 Retrosynthesis with Enolates and Enols
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E2 Elimination of Geminal or Vicinal Dihalides
Alkynes are produced by E2 Elimination of either geminal or vicinal dihalides. A very strong base is required and NaNH2 is the most common and favors formation of terminal alkynes. Grignard reagents (organomagnesium halides) are less commonly used as the base and are not usually presented here as they are generally not introduced until later in the course in the chapter on alcohols, but I include this here as a small percentage of undergraduates will be presented with this fact.
