Fomaldehyde when reacted with methyl magnesium bromide followed by hydrolysis gives (a) HCHO (b) \(\mathrm{CH}_{3} \mathrm{COOH}\) (c) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (d) \(\mathrm{CH}_{3} \mathrm{CHO}\)

The reaction mechanism between aldehydes and Grignard reagents is a fundamental process in organic chemistry, widely utilized for the formation of alcohols. When a Grignard reagent is introduced to an aldehyde, a key step involves the nucleophilic addition of the organomagnesium component to the carbonyl carbon of the aldehyde.

Formaldehyde, as the simplest aldehyde, consists of a carbonyl group (a carbon double-bonded to oxygen) attached to two hydrogen atoms. The partial positive charge on the carbonyl carbon makes it susceptible to nucleophilic attack. In the reaction with formaldehyde, the Grignard reagent serves as the nucleophile, where the carbon adjacent to the magnesium in the Grignard compound has a partial negative charge and attacks the electrophilic carbonyl carbon of formaldehyde.

Following the nucleophilic attack, the oxygen of the carbonyl group acquires a negative charge, leading to the formation of a metal alkoxide intermediate. This intermediate is then ready for the subsequent hydrolysis step, which will convert it into the desired alcohol product. Understanding this mechanism is crucial for predicting the outcome of such reactions and for selecting appropriate conditions and reagents for synthesis objectives.

Grignard reagents are a class of organometallic compounds that have a pivotal role in synthetic organic chemistry. Named after the French chemist Victor Grignard, these reagents have the general formula R-Mg-X, where 'R' represents an alkyl or aryl group and 'X' is a halogen (chlorine, bromine, or iodine).

The unique chemistry of Grignard reagents comes from the carbon-magnesium bond; the carbon is nucleophilic due to the relatively high electronegativity of magnesium compared to carbon. This nucleophilicity allows for the carbon to easily attack electrophiles like the carbonyl carbon found in aldehydes and ketones, forming new carbon-carbon bonds in the process.

Handling and preparation of Grignard reagents require strict anhydrous conditions because they are highly reactive toward water, oxygen, and other protic substances, leading to deactivation. In the context of formaldehyde, methyl magnesium bromide is a Grignard reagent that donates a methyl group to the carbonyl carbon of formaldehyde, which, upon hydrolysis, results in the formation of ethanol. This transformative ability to create new molecular structures is why Grignard reagents are considered invaluable tools in organic synthesis.

Hydrolysis, in organic chemistry, is a reaction involving the breaking of a bond in a molecule using water. This vital process is the final step in the reaction sequence involving Grignard reagents and aldehydes, culminating in the formation of alcohols. Specifically, after the nucleophilic addition of a Grignard reagent to an aldehyde such as formaldehyde, the intermediate metal alkoxide requires hydrolysis to convert it into the final alcohol product.

In the case of the reaction with formaldehyde, hydrolysis involves the addition of water (H₂O), where one hydrogen atom bonds to the oxygen of the alkoxide group, and the OH group bonds to the carbon. This process effectively replaces the metal atom from the metal alkoxide intermediate with a hydroxyl group (-OH), yielding the alcohol. The magnesium from the Grignard reagent ends up in a by-product, often a magnesium hydroxide or halide.

Hydrolysis is not only fundamental in organic synthesis but is also ubiquitous in nature and biological systems. Enzymes specialized for hydrolysis, called hydrolases, drive many biological processes like digestion and metabolism, reflecting the importance of the hydrolysis process in both laboratory synthesis and life's biochemical pathways.