A methyl ether (SN2 product) can form as a byproduct in the sodium methoxide reaction. What is its structure? Provide the mechanism for the formation of the methyl ether product, in addition to answering the question.
To determine the structure of the methyl ether (SN2 product) formed as a byproduct in the sodium methoxide reaction, we first need to understand the reaction and the mechanism involved.
The reaction you mentioned involves sodium methoxide, which is a strong base and a nucleophile. It can react with alkyl halides in a substitution reaction known as an SN2 reaction (Substitution Nucleophilic bimolecular). In this reaction, the nucleophile (methoxide) attacks the electrophilic carbon atom in the alkyl halide, resulting in the substitution of the halogen with the methoxide group.
Based on your question, we will assume that the sodium methoxide is reacting with an alkyl halide, such as methyl iodide (CH3I):
CH3I + NaOCH3 → CH3OCH3 + NaI
The product formed is methyl ether (CH3OCH3), also known as dimethyl ether. Its structure can be represented as follows:
H
|
H - C - O - C - H
|
H
In terms of the mechanism, the reaction proceeds as follows:
1. Nucleophilic Attack: The methoxide ion (CH3O-) acts as a nucleophile and attacks the electrophilic carbon atom in methyl iodide (CH3I). The iodine atom is pushed away, resulting in a transition state where the methoxide is bonded to the carbon atom.
H CH3
| |
H - C - I → C - OCH3
| |
H I
2. Leaving Group Departure: The iodide ion (I-) that was initially bonded to the carbon atom departs, leaving a positively charged carbon atom.
H CH3
| |
H - C - O + CH3
| |
H I
3. Deprotonation: The newly formed carbon with a positive charge (carbocation) is unstable. It is quickly deprotonated by the methoxide ion, forming the methyl ether product.
H CH3
| |
H - C ← O + CH3
| |
H I
Finally, the sodium ion (Na+) present in sodium methoxide acts as a spectator ion and does not participate directly in the formation of the methyl ether product.
Overall, the reaction of sodium methoxide with an alkyl halide leads to the formation of methyl ether (CH3OCH3) as a byproduct through an SN2 mechanism.