[Penguinone]

Give products and mechanism for reaction of triethyl orthoformate with cyclohexanone.

Attempt: see picture below.

Any help will be greatly appreciated.

[Benzene]

Is there water in this reaction mixture?

[Penguinone]

The question didn't say there wasn't any water so I (optimistically) hoped there was.

[Benzene]

The question didn't say there wasn't any water so I (optimistically) hoped there was.

I think you have the correct answer if there is no water in the reaction mixture.

[Penguinone]

Thank you for your reply.
My mechanism does use water though, should I use something else instead of the water molecule? Or just leave the reaction at the point when I use the water?

[Benzene]

triethylorthoformate will decompose in acidic aqueous media.

I think that if you waited until the β addition to the carbonyl was complete, and the triethylorthoformate consumed to add the water, you will create a new product

[Benzene]

Thank you for your reply.
My mechanism does use water though, should I use something else instead of the water molecule? Or just leave the reaction at the point when I use the water?

if there is no water in there, use ethanol to remove protons.

[orgopete]

The difficulty with writing this mechanism is in forming ethanol. Once that is done, you might expect a ketone plus ethanol with acid can form a ketal. You might also expect that the water by-product would keep the reaction from going to completion. However, that water can react with the ortho ester. I suggest you try again.

[Penguinone]

Thank you for your reply. I checked the question again and it doesn't mention water being present.

Attempt 2: see below.

[orgopete]

Acid catalyzed reactions involving enolization of ketones are more difficult. The loss of an alpha hydrogen is probably kinetically less favored than loss from the oxygen. However, if ethanol is present, it can add to the protonated ketone. If you know this chemistry, you know this is an intermediate in ketal formation. The by-product of a ketal is water. Water can react with an ortho ester to give an ester plus ethanol