Predict the product of the following reaction sequences.
(c)

Verified step by step guidance

1. Step 1: Analyze the starting material, which is a cyclic amide (lactam). The structure contains a five-membered ring with an amide group.
2. Step 2: The first reaction involves H2SO4, H2O, and heat. This is typically a hydrolysis reaction where the amide is converted into a carboxylic acid. The cyclic amide will open up to form a linear carboxylic acid.
3. Step 3: The second step involves SOCl2, which is used to convert carboxylic acids into acyl chlorides. The carboxylic acid formed in the previous step will be transformed into an acyl chloride.
4. Step 4: The third step uses LiAlH(Ot-Bu)3, a reducing agent that selectively reduces acyl chlorides to aldehydes. The acyl chloride from the previous step will be reduced to an aldehyde.
5. Step 5: Consider the overall transformation from the cyclic amide to the aldehyde, noting the changes in functional groups and the reagents used at each step.

Key Concepts

Hydrolysis of Lactams

Lactams are cyclic amides that can undergo hydrolysis in the presence of acid and water, especially under heating conditions. This reaction breaks the amide bond, converting the lactam into a linear carboxylic acid and an amine. In this sequence, the use of H2SO4 and heat facilitates the hydrolysis of the lactam ring, leading to the formation of a carboxylic acid.

Conversion of Carboxylic Acids to Acyl Chlorides

Carboxylic acids can be converted into acyl chlorides using thionyl chloride (SOCl2). This reaction involves the substitution of the hydroxyl group of the carboxylic acid with a chlorine atom, forming an acyl chloride. Acyl chlorides are more reactive than carboxylic acids and are useful intermediates in organic synthesis.

Selective Reduction of Acyl Chlorides

Lithium tri-tert-butoxyaluminum hydride (LiAlH(Ot-Bu)3) is a selective reducing agent used to convert acyl chlorides to aldehydes. Unlike other hydride reagents, it does not reduce the aldehyde further to an alcohol. This selectivity is crucial for synthesizing aldehydes from acyl chlorides without over-reduction, allowing for controlled product formation in multi-step synthesis.