Show how this 1° alcohol can be made from the following:

(a) a 1° alkyl bromide

Verified step by step guidance

Step 1: Identify the target molecule, which is a primary alcohol (1° alcohol) with the structure cyclopentylmethanol. This molecule has a hydroxyl (-OH) group attached to a primary carbon that is directly bonded to a cyclopentyl group.

Step 2: Recognize that the starting material is a primary alkyl bromide. A suitable primary alkyl bromide for this synthesis would be cyclopentylmethyl bromide, where the bromine atom is attached to the same primary carbon as in the target alcohol.

Step 3: Plan the reaction mechanism. To convert a primary alkyl bromide to a primary alcohol, a nucleophilic substitution reaction (SN2 mechanism) can be used. In this reaction, the bromine atom is replaced by a hydroxyl group (-OH).

Step 4: Select the reagent for the substitution reaction. Sodium hydroxide (NaOH) or potassium hydroxide (KOH) in an aqueous solution can act as the nucleophile, providing the hydroxide ion (OH⁻) needed for the substitution.

Step 5: Write the reaction. Cyclopentylmethyl bromide reacts with hydroxide ion (OH⁻) in an SN2 reaction to produce cyclopentylmethanol and sodium bromide (NaBr) as a byproduct. Ensure the reaction conditions favor SN2, such as using a polar aprotic solvent if necessary.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Nucleophilic Substitution

Nucleophilic substitution is a fundamental reaction in organic chemistry where a nucleophile replaces a leaving group in a molecule. In the case of converting a 1° alkyl bromide to a 1° alcohol, a nucleophile, typically hydroxide ion (OH-), attacks the carbon atom bonded to the bromine, displacing the bromine atom and forming the alcohol.

1° Alkyl Bromide

A 1° alkyl bromide is a type of organic compound where a bromine atom is attached to a primary carbon atom, which is connected to only one other carbon atom. This structure is significant because it influences the reactivity and mechanism of nucleophilic substitution reactions, often favoring the SN2 pathway due to less steric hindrance.

SN2 Mechanism

The SN2 mechanism (substitution nucleophilic bimolecular) is a type of nucleophilic substitution that involves a single concerted step where the nucleophile attacks the electrophilic carbon as the leaving group departs. This mechanism is characteristic of primary substrates like 1° alkyl bromides, leading to inversion of configuration at the carbon center.

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