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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Mahmedgamel on September 10, 2022, 05:46:31 AM

Title: Organic reaction
Post by: Mahmedgamel on September 10, 2022, 05:46:31 AM

Kindly, I need an explanation for this problem.

Title: Re: Organic reaction
Post by: rolnor on September 11, 2022, 11:26:16 AM

Whats your thoughts?

Title: Re: Organic reaction
Post by: Mahmedgamel on September 14, 2022, 06:47:04 AM

The fourth option will be, I think, Because HMTA will do insertion of CHO group in third position, then cyclization will happen by abstraction of that proton which near to the CO2Et group then elimination of water and aromatization generated. There was a CO2Et missing in the forth option in that image. I attached a new image Kindly have a look at that.

Title: Re: Organic reaction
Post by: rolnor on September 14, 2022, 10:39:02 AM

I think its correct

Title: Re: Organic reaction
Post by: Mahmedgamel on September 14, 2022, 10:48:12 AM

Thanks.

Title: Re: Organic reaction
Post by: rolnor on September 15, 2022, 09:12:32 AM

Its missing one step, the decarboxylation, so 3 could be right.

Title: Re: Organic reaction
Post by: Mahmedgamel on September 16, 2022, 04:55:40 AM

I think CHO group insertion will not happen at C2. It will happen at C3 due to the stable resonance structure, and the octet of the pyridine ring will be affected by resonance.
Then, if given hydrolysis and heat, the product will be the fourth option, as shown in image 500. But that image was cropped to the CO2Et in the fourth option. So I think the fourth option is correct. As shown in image 501, hydrolysis and heat are not given in question.