So i think this is a hydrolysis of an ester, but I'm not sure. If it is, do I need to add water as a solvent? Most of the examples I have seen with an ester under basic conditions is that there is H2O written alongside the anionic base. 

Thanks in advance 

Edited February 26, 20187 yr by nancy9494
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I think you need to start by counting your carbons. They don't look like they match between your reagent / reactant and your product. You might also like to consider the feasibility of your sulfur reagent. 

@OP, If you have a sodium as a countering, what does that suggest about the rest of the reagent?

If you are doing ester hydrolysis under basic conditions, you would need water to finish the reaction. Water can be added directly or be part of the solvent system.

I think there is an error . CH3SO2 is wrong.

It is sodium and Dimethylsulfon (CH3)2SO2 as reactant this forms the CH active sodium salt CH3SO2CH2- + Na+.

This will attack the Ester and the Methanolate will be pushed out. No water involved.

RCO-OCH3 + CH3SO2CH2- => RCO-CH2SO2CH3 + CH3O-

This will be neutralised with mild acid.

Edited February 2Feb 2 by chenbeier

You're absolutely right to identify this as an ester hydrolysis under basic conditions. In base-catalyzed ester hydrolysis (also known as saponification), water is not only useful as a solvent, but it is essential as the nucleophile that participates in the mechanism.

The hydroxide ion (OH⁻) from NaOH attacks the carbonyl carbon of the ester, forming a tetrahedral intermediate, which then eliminates the alkoxide group (e.g., CH₃O⁻) and yields the carboxylate anion. The presence of H₂O in the reaction mixture helps maintain the ionic environment and allows for proton transfers, especially in the final neutralization step with H₃O⁺, as shown in your reaction scheme.

So yes, water is absolutely necessary here—not just as solvent, but as a participant in the reaction mechanism.

You're absolutely right to identify this as an ester hydrolysis under basic conditions. In base-catalyzed ester hydrolysis (also known as saponification), water is not only useful as a solvent, but it is essential as the nucleophile that participates in the mechanism.

The hydroxide ion (OH⁻) from NaOH attacks the carbonyl carbon of the ester, forming a tetrahedral intermediate, which then eliminates the alkoxide group (e.g., CH₃O⁻) and yields the carboxylate anion. The presence of H₂O in the reaction mixture helps maintain the ionic environment and allows for proton transfers, especially in the final neutralization step with H₃O⁺, as shown in your reaction scheme.

So yes, water is absolutely necessary here—not just as solvent, but as a participant in the reaction mechanism.

First why you post your text twice.

I don't agree, if you use NaOH, and get water, how you connect the Sulton? Not possible then. There is no NaOH used.

Edited May 12May 12 by chenbeier

This is saponification. Sodium methoxide and water. The methoxide ion is the nucleophile and attacks the carbonyl carbon and the water works as the solvent supporting the reaction environment and maintaining the ionic species. So yes, you are right. Adding water is necessary because the medium would be too dry to allow proper ion stabilization. As for the mild acid, it protonates the salt formed in the first step.

Where you get the sodium methoxide as reactant. It's one of the product.

The reactans are the Ester, sodium and dimethylsulton.

2 CH3SO2CH3 + 2 Na => 2 CH3SO2CH2- + 2 Na+ + H2

RCO-OCH3 + CH3SO2CH2- => RCO-CH2SO2CH3 + CH3O-

Edited May 12May 12 by chenbeier