Question

Question #db577

Answer 1

Here's what I got.

Explanation:

So, methylmagnesium bromide, `"CH"_3"MgBr"`, which is a Grignard reagent, will react with cyclohexanone, `("CH"_2)_5"CO"`, to produce 1-methylcyclohexanol, `"CH"_3"C"_6"H"_10"OH"`.

The reaction will also produce `"Mg"("OH")"Br"`, but, depending on which reaction conditions you use, you can represent this compound as ions.

Here's how the mechanism for this reaction looks like

https://web.chemdoodle.com/demos/sketcher/

As you know, the difference in electronegativity between carbon and oxygen results in a polar carbon - oxygen bond.

This means that the carbon attached to the oxygen via a double bond, i.e. the one belonging to the carbony group, will be electron deficient.

Grignard reagents act as nucleophiles and attack this electron-deficient carbon, adding across the `"C"="O"` double bond - this is actually known as an alkylation reaction.

Here's where you have a choice for the mechanism. The next step involves the hydrolysis of the intermediary product, which is called a Grignard salt, to form the desired alcohol.

You can do this in one of two ways

• you can add water
• you can add a dilute acid

I think that if you're interested in isolating the resulting alcohol, you should add a dilute acid. I'm not sure about the nature of this salt, by I think that the acid will react with `"Mg"("OH")"Br"` and convert it to ions.

`"Mg"("OH")"Br" + "H"_3"O"_text((aq])^(+) -> "Mg"_text((aq])^(2+) + "Br"_text((aq])^(-) + 2"H"_2"O"_text((l])`

I chose this option - the weak acid is represented by `"OH"_3^(+)` in the above mechanism diagram.