8 P - Organic Chemistry (Mcmurry)

Question

 

Question: What carbonyl compounds give the following alcohols on reduction with ? Show all possibilities.

(a)

(b)

(c)

(d) ${\left({\mathbf{CH}}_{\mathbf{3}}\right)}_{\mathbf{2}}{\mathbf{CHCH}}_{\mathbf{2}}\mathbf{OH}$

Step-by-Step Solution

Answer

(a)

(b) 

(c) 

(d)

Step 1: Preparation of alcohols from carbonyl compounds

Alcohols from carbonyl compounds can be prepared by identifying the type of target alcohol, whether it is primary, secondary, or tertiary. The primary alcohol is obtained by reducing three functional groups (carboxylic acid, ester, and aldehyde), and secondary alcohol is obtained by reducing ketone.

Step 2: The carbonyl compounds needed to form alcohol (a)

 (a) Benzyl alcohol is formed by reducing aldehyde, carboxylic acid, or an ester. The reagent used is because it reduces both ketones and esters groups, and the reagent may be used to reduce the aldehyde group.

Alcohol from a carbonyl compound

Step 3: The carbonyl compounds needed to form alcohol (b)

(b) The reduction of the ketone group forms the secondary alcohol product. The reagent used is because it yields secondary alcohol. The reagent may also be used here.

Alcohol from a carbonyl compound

Step 4: The carbonyl compounds needed to form alcohol (c)

(c) A secondary alcohol product is formed by reducing the ketone group in the starting material. The reagent used is because it yields secondary alcohol. The reagent may also be used here.

Alcohol from a carbonyl compound

Step 5: The carbonyl compounds needed to form alcohol (d)

(d) A primary alcohol product is formed by reducing aldehyde, carboxylic acid, and ester group as the starting material. The reagent used is because it is the stronger reducing agent. 

Alcohol from a carbonyl compound