I have tried these questions on my own but am wondering if someone wouldn't mind trying these retrosyntheses and list their steps to see if they get the same as me:
1) start with m-cresol which is toluene with an OH in the meta position.
end with musk-ambrette whose structure is as follows: a toluene with an NO2 group in each ortho position, a CH3O in the meta position and a (CH3)2CH in the para position.
2) start with cholorobenzene.
end with a benzene ring whose structure is as follows: taking 1 NO2 group as the reference point, there is an SCH2CH3 in the ortho position and an CH3C=O in the meta position.
Thanks so much.
Sure! I'd be happy to help you with the retrosynthesis of these compounds. I'll provide step-by-step explanations for each retrosynthesis.
1) Retrosynthesis of musk-ambrette:
Starting material: m-cresol (toluene with an OH in the meta position)
Target product: musk-ambrette (a toluene with an NO2 group in each ortho position, a CH3O in the meta position, and a (CH3)2CH in the para position)
To achieve the target compound, we need to think backwards and break down musk-ambrette into simpler starting materials. Here are the steps:
Step 1: Conversion of (CH3)2CH group in para position
- (CH3)2CH has a structure similar to an isopropyl group.
- The retrosynthesis suggests starting with acetone (CH3COCH3). You can see that by losing a water molecule, we can form an isopropyl group, (CH3)2CH.
Step 2: Conversion of CH3O group in meta position
- The CH3O group suggests starting with methanol (CH3OH).
- By performing an oxidation reaction on methanol, we can introduce the CH3O group to the meta position. This oxidation reaction can be carried out using various oxidizing agents, such as chromic acid (H2CrO4).
Step 3: Conversion of NO2 groups in the ortho positions
- NO2 groups suggest starting with nitrobenzene (C6H5NO2). Each NO2 group can be introduced using nitration reactions.
- Nitration is typically carried out using a mixture of nitric acid (HNO3) and sulfuric acid (H2SO4) as the nitrating agent.
By connecting the retrosynthetic steps together, we can achieve the retrosynthesis of musk-ambrette as follows:
Acetone + Methanol + Nitrobenzene (with nitration reactions)
--> (CH3)2CH in para position + CH3O in meta position + NO2 groups in ortho positions
Starting from these three simpler compounds, you can perform the necessary reactions to synthesize musk-ambrette.
2) Retrosynthesis of the benzene compound:
Starting material: Chlorobenzene
Target product: Benzene with an SCH2CH3 in the ortho position and a CH3C=O in the meta position (relative to one NO2 group)
To achieve the target compound, we need to think backwards and break down the benzene compound into simpler starting materials. Here are the steps:
Step 1: Conversion of SCH2CH3 group in ortho position
- SCH2CH3 suggests starting with ethyl mercaptan (C2H5SH).
- By performing an alkylation reaction, we can introduce the SCH2CH3 group in the ortho position. This reaction can be carried out using an appropriate alkylating agent, such as methyl iodide (CH3I), and a base, like sodium hydroxide (NaOH).
Step 2: Conversion of CH3C=O group in meta position
- CH3C=O suggests starting with acetophenone (C6H5C(O)CH3).
- The retrosynthesis shows that the CH3C=O group can be introduced using a Friedel-Crafts acylation reaction. This reaction involves the reaction of an acyl chloride (or acid anhydride) with benzene in the presence of a Lewis acid catalyst, such as aluminum chloride (AlCl3).
By connecting the retrosynthetic steps together, we can achieve the retrosynthesis of the benzene compound as follows:
Ethyl mercaptan + Acetophenone (with Friedel-Crafts acylation)
--> SCH2CH3 in ortho position + CH3C=O in meta position (relative to one NO2 group)
Starting from these two simpler compounds, you can perform the necessary reactions to synthesize the benzene compound.
I hope this helps!