Textbook Question
Answer Problem 39 , parts a–h, using 2-butyne as the starting material instead of propyne.
d. Br2 (2 mol)/CH2Cl2
1
views
Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 1)31
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 2)65
- Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry84
- Ch. 3 - An Introduction to Organic Compounds:Nomenclature, Physical Properties, and Structure183
- Ch. 4 - Isomers: The Arrangement of Atoms in Space121
- Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics83
- Ch. 6 - The Reactions of Alkenes • The Stereochemistry of Addition Reactions175
- Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis119
- Ch. 8 - Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene148
- Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides212
- Ch. 10 - Reactions of Alcohols, Ethers, Epoxides, Amines, and Sulfur-Containing Compounds131
- Ch. 11 - Organometallic Compounds60
- Ch. 12 - Radicals90
- Ch. 13 - Mass Spectrometry; Infrared Spectroscopy; UV/Vis Spectroscopy62
- Ch. 14 - NMR Spectroscopy95
- Ch. 15 - Reactions of Carboxylic Acids and Carboxylic Acid Derivatives123
- Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives141
- Ch. 17 - Reactions at the Alpha-Carbon101
- Ch. 18 - Reactions of Benzene and Substituted Benzenes144
- Ch. 19 - More About Amines • Reactions of Heterocyclic Compounds49
- Ch. 20 - The Organic Chemistry of Carbohydrates80
- Ch. 21 - Amino Acids, Peptides, and Proteins57
- Ch. 22 - Catalysis in Organic Reactions and in Enzymatic Reactions35
- Ch. 23 - The Organic Chemistry of the Coenzymes—Compounds Derived from Vitamins1
- Ch. 28 - Pericyclic Reactions58
All textbooks
Bruice 8th EditionCh. 7 - The Reactions of Alkynes • An Introduction to Multistep SynthesisProblem 40g
Bruice 8th EditionCh. 7 - The Reactions of Alkynes • An Introduction to Multistep SynthesisProblem 40gChapter 8, Problem 40g
Answer Problem 39, parts a–h, using 2-butyne as the starting material instead of propyne.
g. excess H2, Pd/C
Verified step by step guidance1
Identify the starting material: The starting material is 2-butyne, which is an alkyne with the structure CH3-C≡C-CH3. It contains a triple bond between the second and third carbons.
Understand the reaction conditions: The reaction involves excess H2 (hydrogen gas) and Pd/C (palladium on carbon), which is a catalyst used for hydrogenation reactions. Excess H2 ensures complete hydrogenation of the alkyne.
Determine the reaction type: This is a catalytic hydrogenation reaction. In the presence of Pd/C and excess H2, the alkyne will undergo complete hydrogenation, converting the triple bond into a single bond by adding hydrogen atoms.
Write the reaction mechanism: The triple bond in 2-butyne will first be reduced to a double bond (alkene) by the addition of two hydrogen atoms. Then, the double bond will be further reduced to a single bond (alkane) by the addition of two more hydrogen atoms. The final product will be an alkane.
Predict the product: The complete hydrogenation of 2-butyne will result in butane (CH3-CH2-CH2-CH3), as all π bonds in the alkyne are replaced with σ bonds by the addition of hydrogen atoms.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Alkyne Hydrogenation
Hydrogenation of alkynes involves the addition of hydrogen (H2) across the triple bond, converting it into an alkene or alkane. In the presence of a catalyst like palladium on carbon (Pd/C), this reaction can proceed efficiently. For 2-butyne, excess H2 will fully saturate the triple bond, resulting in the formation of butane.
Recommended video:
Guided course
03:46
Using Catalytic hydrogenation or Wilkinson’s Catalyst to turn alkynes to alkanes.
Catalytic Hydrogenation
Catalytic hydrogenation is a process where hydrogen gas is added to unsaturated organic compounds in the presence of a catalyst. The catalyst lowers the activation energy required for the reaction, allowing for faster conversion. In this case, Pd/C serves as an effective catalyst for the hydrogenation of 2-butyne to butane.
Recommended video:
Guided course
05:21General properties of catalytic hydrogenation.
Reaction Mechanism
Understanding the reaction mechanism is crucial for predicting the outcome of chemical reactions. In the case of hydrogenation, the mechanism involves the adsorption of the alkyne onto the catalyst surface, followed by the addition of hydrogen atoms to the carbon atoms of the triple bond. This stepwise process leads to the formation of the saturated product, butane, from 2-butyne.
Recommended video:
Guided course
02:16Heck Reaction Mechanism
Related Practice
Textbook Question
What is each compound's systematic name?
b.
Textbook Question
Answer Problem 39, parts a–h, using 2-butyne as the starting material instead of propyne.
h. H2/Lindlar catalyst
1
views
Textbook Question
Answer Problem 39, parts a–h, using 2-butyne as the starting material instead of propyne.
e. aqueous H2SO4, HgSO4
2
views
Textbook Question
What is each compound's systematic name?
a. CH3C☰CCH2CH2CH2CH═CH2
3
views
Textbook Question
Answer Problem 39, parts a–h, using 2-butyne as the starting material instead of propyne.
f. R2BH in THF followed by H2O2/HO− /H2O
2
views