Domanda del libro di testo
Unlike hydroboration–oxidation, the addition of H2O catalyzed by H3O+ is not stereospecific. Thinking carefully about the mechanism of the reaction, give two reasons why.
1299
views
Ch. 8 - Alkenes 1: Properties and Electrophilic Additions
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471
Non è quello che usi tu?Cambia libro di testoScegli un libro di testo diverso
TOC.tableOfContents
- Ch. 2 - General Chemistry Translated: Finding the Electrons114
- Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis109
- Ch. 4 - Acids and Bases/Electron Flow144
- Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics118
- Ch. 6 - Stereoisomerism: Arrangement of Atoms in Space112
- Ch. 7 - Principles of Green (Organic) Chemistry3
- Ch. 8 - Alkenes 1: Properties and Electrophilic Additions158
- Ch. 9 - Alkenes 2: Oxidation and Reduction150
- Ch. 10 - Alkynes: Electrophilic Addition and Redox Reactions101
- Ch. 11 - Properties and Synthesis of Alkyl Halides: Radical Reactions108
- Ch. 12 - Substitution and Elimination: Reactions of Haloalkanes172
- Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination239
- Ch. 14 - Structural Identification 1: Infrared Spectroscopy and Mass Spectrometry54
- Ch. 15 - Structural Identification 2: Nuclear Magnetic Resonance Spectroscopy93
- Ch. 16 - Metals in Organic Chemistry48
- Ch. 17 - Carbonyl Addition Reactions: Aldehydes and Ketones45
- Ch. 18 - Nucleophilic Acyl Substitution 1: Carboxylic Acids18
- Ch. 19 - Nucleophilic Acyl Substitution 2: Carboxylic Acid Derivatives39
- Ch. 20 - Enolates: Carbonyl Addition and Substitution13
- Ch. 21 - Conjugated Systems 1: Stability and Addition Reactions56
- Ch. 22 - Conjugated Systems 2: Pericyclic Reactions54
- Ch. 23 - Benzene 1: Aromatic Stability and Substitution Reactions64
- Ch. 24 - Benzene 2: Reactions Influenced by the Aromatic Ring62
- Ch. 25 - Amines: Structure, Reactions, and Synthesis27
- Ch. 26 - Amino Acids, Proteins, and Peptide Synthesis9
- Ch. 27 - Carbohydrates, Nucleic Acids, and Lipids54
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testo
Mullins 1st EditionCh. 8 - Alkenes 1: Properties and Electrophilic AdditionsProblema 57
Mullins 1st EditionCh. 8 - Alkenes 1: Properties and Electrophilic AdditionsProblema 57Capitolo 7, Problema 57
The first step of oxymercuration–reduction is stereospecific, and yet this fact wasn't emphasized in that discussion. Show the stereospecificity of the first step for the following alkene and then explain why the stereospecificity becomes unimportant after the second step.
Guida verificata passo dopo passo1
Identify the alkene structure involved in the oxymercuration-reduction reaction. The alkene will undergo an addition reaction with mercuric acetate (Hg(OAc)₂) in the presence of water.
Understand that the first step of oxymercuration involves the formation of a mercurinium ion intermediate. This step is stereospecific because the addition of the mercuric acetate occurs from one side of the double bond, leading to a specific stereochemistry in the intermediate.
Illustrate the formation of the mercurinium ion. The alkene's π electrons attack the mercury atom, forming a cyclic mercurinium ion. This intermediate is crucial as it dictates the stereochemistry of the subsequent nucleophilic attack.
Explain that the stereospecificity becomes unimportant after the second step, which is the reduction step. In this step, sodium borohydride (NaBH₄) is used to reduce the mercurinium ion, replacing the mercury with a hydrogen atom. This reduction step is not stereospecific, as it can occur from either side of the intermediate, leading to a mixture of stereoisomers.
Conclude by emphasizing that while the first step is stereospecific, the overall reaction results in a racemic mixture due to the non-stereospecific nature of the reduction step. This is why the stereospecificity of the first step is not emphasized in the overall reaction outcome.
Risposta video verificata per un problema simile:
Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
14mConcetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
Oxymercuration-Reduction Mechanism
Oxymercuration-reduction is a two-step reaction used to convert alkenes into alcohols. The first step involves the addition of mercuric acetate to the alkene, forming a mercurinium ion intermediate. This step is stereospecific, meaning it occurs with a specific spatial arrangement, often leading to anti-addition. The second step involves reduction with sodium borohydride, which replaces the mercury with a hydrogen atom, completing the transformation to an alcohol.
Video consigliato:
09:01
Acid-catalyzed oxymercuration-reduction mechanism
Stereospecificity in Chemical Reactions
Stereospecificity refers to a reaction where a particular stereoisomer of a reactant leads to a specific stereoisomer of the product. In the context of oxymercuration, the formation of the mercurinium ion intermediate is stereospecific, as it dictates the spatial arrangement of atoms in the product. This specificity is crucial in the first step but becomes less relevant in the second step due to the reduction process, which does not alter the stereochemistry established earlier.
Video consigliato:
Percorso guidato
3:11Chemical Reactions of Phosphate Anhydrides Concept 1
Importance of Stereochemistry in Reduction
During the reduction step of oxymercuration-reduction, the stereochemistry established in the first step becomes unimportant because the reduction with sodium borohydride is not stereospecific. This step involves the replacement of the mercury atom with a hydrogen atom, which does not affect the spatial arrangement of the remaining atoms. Thus, the stereochemical outcome of the first step does not influence the final product's stereochemistry.
Video consigliato:
Percorso guidato
1:38Polymer Stereochemistry Concept 1
Pratica correlata
Domanda del libro di testo
Suggest an alkene to undergo hydroboration–oxidation (1. BH3 2. NaOH, H2O2) to give exclusively the alcohols shown. Pay close attention to the relative (but not absolute) stereochemical outcome.
(d)
1853
views
Domanda del libro di testo
Calculate the index of hydrogen deficiency for the following molecular formulas and structures.
(c)
1229
views
Domanda del libro di testo
Predict the major product(s) of the following elimination reactions, paying close attention to the stereochemical outcome of the reactions.
(e)
863
views
Domanda del libro di testo
Calculate the index of hydrogen deficiency for the following molecular formulas and structures.
(a)
1135
views
Domanda del libro di testo
Calculate the index of hydrogen deficiency for the following molecular formulas and structures.
(b)
1365
views