Skip to main content
Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives
Bruice - Organic Chemistry 8th Edition
Bruice8th EditionOrganic ChemistryISBN: 9780135213711Non è quello che usi tu?Cambia libro di testo
Capitolo 16, Problema 13a(1)

Show how the following compounds can be prepared, using ethyne as one of the starting materials:
1. 1-pentyn-3-ol

Guida verificata passo dopo passo
1
Step 1: Begin with ethyne (C₂H₂) as the starting material. Perform a reaction with sodium amide (NaNH₂) to generate the acetylide ion (C≡C⁻), which is a strong nucleophile.
Step 2: Perform an alkylation reaction by reacting the acetylide ion with 1-bromopropane (CH₃CH₂CH₂Br). This will extend the carbon chain, forming 1-butyne (CH≡C-CH₂CH₂CH₃).
Step 3: To introduce the hydroxyl group (-OH) at the desired position, perform a hydroboration-oxidation reaction. First, react 1-butyne with a bulky borane reagent, such as disiamylborane [(sia)₂BH], to ensure anti-Markovnikov addition of the boron atom.
Step 4: Oxidize the organoborane intermediate using hydrogen peroxide (H₂O₂) in the presence of a base (e.g., NaOH). This will replace the boron atom with a hydroxyl group, yielding 1-pentyn-3-ol.
Step 5: Verify the structure of the product to ensure that the hydroxyl group is located on the third carbon of the pentynyl chain, confirming the synthesis of 1-pentyn-3-ol.

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:
6m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Ethyne as a Building Block

Ethyne, also known as acetylene, is a simple alkyne that serves as a versatile building block in organic synthesis. Its triple bond allows for various reactions, including addition reactions with electrophiles, which can lead to the formation of more complex molecules. Understanding how to manipulate ethyne in synthetic pathways is crucial for preparing target compounds.
Video consigliato:
16:59
Building a molecular sentence

Alkyne Reactions

Alkynes undergo a variety of reactions, including hydration, hydroboration, and oxidation. In the case of preparing 1-pentyn-3-ol, the hydration of an alkyne can be achieved through acid-catalyzed reactions, leading to the formation of alcohols. Familiarity with these reactions and their mechanisms is essential for constructing the desired compound from ethyne.
Video consigliato:
01:01
General properties of double addition reactions to alkynes.

Functional Group Transformation

Functional group transformations involve converting one functional group into another, which is a key strategy in organic synthesis. In this context, transforming an alkyne into an alcohol requires specific reagents and conditions. Understanding how to effectively perform these transformations is vital for synthesizing compounds like 1-pentyn-3-ol from ethyne.
Video consigliato:
02:36
Identifying Functional Groups