Question

When 1-bromopropane is exposed to magnesium, followed by ethanal (a 2-carbon aldehyde) and then aqueous acid, what is the resulting product

Answer 1

The reaction of 1-bromopropane with magnesium to form a Grignard reagent, followed by reaction with ethanal and acidic workup, yields 2-propyl-1-propanol.

Step-by-step explanation:

When 1-bromopropane is exposed to magnesium, a Grignard reagent is formed. This reagent then reacts with ethanal in a nucleophilic addition to form a secondary alcohol. Finally, the addition of aqueous acid will protonate the alkoxide intermediate to give the alcohol as the main product. The specific sequence of reactions is:

1. 1-bromopropane + Mg → Propylmagnesium bromide (Grignard reagent).
2. Propylmagnesium bromide + ethanal → 2-propylpropan-1-ol (after aqueous acid workup).

The overall result is the formation of 2-propyl-1-propanol.

Answer 2

The reaction between 1-bromopropane, magnesium, ethanal, and aqueous acid results in the formation of 2-butanol. This sequence includes the formation of a Grignard reagent, its reaction with an aldehyde, and eventual protonation to give the alcohol.

Step-by-step explanation:

The student is asking about a reaction involving 1-bromopropane, magnesium, ethanal (also known as acetaldehyde), and an aqueous acid. This is a multi-step synthetic reaction that forms a new organic compound.

When 1-bromopropane is exposed to magnesium, a Grignard reagent is formed, which in this case is propylmagnesium bromide. The Grignard reagent then reacts with ethanal, producing a secondary alcohol after the addition of the alkyl group from the Grignard reagent to the carbonyl carbon of the aldehyde. Finally, the secondary alcohol undergoes protonation upon treatment with the aqueous acid to yield the final product. The expected product from this sequence would be 2-butanol, which is an alcohol with four carbon atoms, including the original propyl chain and the additional carbon from ethanal.