Skip to main content
Ch. 15 - Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728Non è quello che usi tu?Cambia libro di testo
Capitolo 15, Problema 13b

Show how you might synthesize the following compounds starting with bromobenzene, and alkyl or alkenyl halides of four carbon atoms or fewer.
b. 5-methylhex-2-ene

Guida verificata passo dopo passo
1
Step 1: Begin with bromobenzene as the starting material. Perform a Friedel-Crafts alkylation reaction using a suitable alkyl halide (e.g., 1-bromopropane) and a Lewis acid catalyst such as AlCl₃. This will introduce a propyl group onto the benzene ring, forming propylbenzene.
Step 2: Perform a benzylic bromination on the propylbenzene using N-bromosuccinimide (NBS) and light (hv) to selectively brominate the benzylic position, forming 1-bromo-3-phenylpropane.
Step 3: Carry out a Wurtz reaction by reacting 1-bromo-3-phenylpropane with an alkyl halide (e.g., methyl iodide) in the presence of sodium metal. This will couple the two alkyl chains, forming 5-phenylhexane.
Step 4: Perform a dehydrohalogenation reaction to introduce a double bond. Use a strong base such as potassium tert-butoxide (t-BuOK) to eliminate a hydrogen and a halogen, forming 5-phenylhex-2-ene.
Step 5: Finally, perform a hydrogenation reaction using a catalyst such as Pd/C and hydrogen gas (H₂) to selectively remove the phenyl group, leaving behind 5-methylhex-2-ene as the desired product.

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:
5m

Concetti chiave

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

Electrophilic Aromatic Substitution

Electrophilic aromatic substitution (EAS) is a fundamental reaction in organic chemistry where an electrophile replaces a hydrogen atom on an aromatic ring. In the case of bromobenzene, the bromine atom can be replaced by various electrophiles, allowing for the introduction of different substituents. Understanding EAS is crucial for synthesizing compounds from aromatic starting materials.
Video consigliato:
03:07
EAS Review

Alkylation Reactions

Alkylation reactions involve the introduction of an alkyl group into a molecule, often through nucleophilic substitution or EAS. When synthesizing 5-methylhex-2-ene, alkyl halides can be used to add carbon chains to the aromatic ring or to create branched alkenes. Mastery of alkylation techniques is essential for constructing complex organic molecules.
Video consigliato:
03:19
Sodium Alkynide Alkylation

Elimination Reactions

Elimination reactions are processes where two atoms or groups are removed from a molecule, resulting in the formation of a double bond. In the synthesis of 5-methylhex-2-ene, elimination reactions can be employed to convert alkyl halides into alkenes. Understanding the mechanisms and conditions for elimination is vital for achieving the desired product in organic synthesis.
Video consigliato:
00:40
Recognizing Elimination Reactions.