Question

Complete each synthesis by giving missing starting material, reagent or products:

Hint:

The reactions here involve common organic transformations such as imine formation, ozonolysis, and Friedel-Crafts acylation. Always pay attention to the reagents used to identify the transformation.

Answer 1

(a) The given reaction is the formation of an imine (Schiff base). The starting material is a ketone, cyclohexanone (C\(_6\)H\(_8\)O), reacting with ammonia (NH\(_3\)) in acidic medium (H\(^+\)) to form an imine.
The reaction is: \[ \text{Cyclohexanone} + \text{NH}_3 \xrightarrow{H^+} \text{Imine (Schiff base)} \]
(b) This reaction represents the ozonolysis of a cyclohexene derivative. The starting material for this reaction is cyclohexene, which undergoes ozonolysis (O\(_3\)) followed by reduction with zinc (Zn) and water (H\(_2\)O) to give a diketone as the final product.
The reaction is: \[ \text{Cyclohexene} \xrightarrow{O_3} \text{Diketone intermediate} \xrightarrow{\text{Zn/H}_2\text{O}} \text{Cyclohexanone} \]
(c) This reaction involves the conversion of a diol (vicinal diol) to a ketone via the reaction with thionyl chloride (SOCl\(_2\)) at elevated temperature (\(\Delta\)). The starting material is a cyclohexane diol, which reacts to form a cyclohexanone derivative.
The reaction is: \[ \text{Cyclohexane-1,2-diol} \xrightarrow{\text{SOCl}_2, \Delta} \text{Cyclohexanone} \]
(d) This reaction represents the conversion of an aldehyde to an acid via a nucleophilic substitution reaction. The starting material is a compound with both an aldehyde and a carboxyl group (like 3-phenylpropionaldehyde). Sodium cyanide (NaCN) in hydrochloric acid (HCl) facilitates this transformation.
The reaction is: \[ \text{Aldehyde} + \text{NaCN/HCl} \rightarrow \text{Carboxylic acid} \]
(e) This reaction involves the Friedel-Crafts acylation of benzene using acetyl chloride (CH\(_3\)COCl) in the presence of a Lewis acid (like AlCl\(_3\)) to form acetophenone.
The reaction is: \[ \text{Benzene} + \text{CH}_3\text{COCl} \xrightarrow{\text{AlCl}_3} \text{Acetophenone} \]