Problem 47 - Chemistry The Molecular Science

Question

Melissyl cerotate has this structural formula: CCCC(=O)OCC (a) Identify the type of compound melissyl cerotate is. (b) Write the structural formulas of the compounds produced by the hydrolysis of melissyl cerotate.

Step-by-Step Solution

Answer

Melissyl cerotate is an ester. Hydrolysis yields butanoic acid and ethanol.

Step 1: Determine the Type of Compound

The SMILES representation given, `CCCC(=O)OCC`, indicates that melissyl cerotate contains an ester functional group, depicted by the sequence `C(=O)OC`. Esters are organic compounds formed from an alcohol and a carboxylic acid.

Step 2: Write the Hydrolysis Reaction

During the hydrolysis of an ester, the compound reacts with water to produce a carboxylic acid and an alcohol. The general reaction is: \[ RCOOR' + H_2O \rightarrow RCOOH + R'OH \]where \(RCOOR'\) is the ester, \(RCOOH\) is the carboxylic acid, and \(R'OH\) is the alcohol.

Step 3: Identify the Hydrolysis Products

Given the ester `CCCC(=O)OCC`, apply the hydrolysis reaction: 1. **Carboxylic Acid:** The compound left after severing the ester bond linking oxygen will be `CCCC(=O)OH`, which corresponds to butanoic acid. 2. **Alcohol:** The group attached to the oxygen `OCC`, becomes the alcohol `C2H5OH` or ethanol.

Step 4: Draw Structural Formulas of Hydrolysis Products

1. **Butanoic Acid:** The structural formula is ``` CH3-CH2-CH2-C(=O)OH ``` This is a four-carbon chain with a carboxyl group (-COOH) at the end. 2. **Ethanol:** The structural formula is ``` CH3-CH2-OH ``` This is a two-carbon alcohol with a hydroxyl group (-OH).

Key Concepts

Ester Hydrolysis

Ester hydrolysis is a fundamental reaction in organic chemistry where an ester is broken down into its constituent components, an alcohol and a carboxylic acid. This process is typically facilitated by the addition of water, and often requires an acid or a base to drive the reaction forward.
The mechanism of ester hydrolysis can vary depending on the conditions:

• Acid-catalyzed hydrolysis: Involves the protonation of the ester which makes it more susceptible to attack by water.
• Base-catalyzed hydrolysis (saponification): Also common, particularly in producing soaps, where a strong base is used instead of water alone.

During hydrolysis, the ester bond is cleaved, resulting in one molecule taking the acyl group and forming a carboxylic acid, while the other gains a hydroxyl group, forming an alcohol. This general reaction can be depicted as: \[ RCOOR' + H_2O \rightarrow RCOOH + R'OH \]
where \(RCOOR'\) is the ester, \(RCOOH\) is the carboxylic acid, and \(R'OH\) is the alcohol.

Carboxylic Acids

Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group (-COOH). They are widely found in nature and are important in many biological and chemical processes.
These compounds typically exhibit:

• Acidic properties, due to the hydrogen in the carboxyl group being easily released as a proton (H⁺).
• Solubility in water, though this decreases with longer carbon chains.
• A distinct sour taste and strong odors.

One of the simplest carboxylic acids is butanoic acid (C₃H₇COOH), resulting from the hydrolysis of many esters, including melissyl cerotate.
Butanoic acid illustrates the typical structure and behavior of these acids: it features a four-carbon chain and exhibits the reactivity and properties expected from carboxyl-containing compounds.

Alcohol Formation

Alcohols are organic compounds defined by the presence of one or more hydroxyl groups (-OH) attached to a carbon atom. They are commonly derived from the hydrolysis of esters and are versatile in their uses.
Characteristics of alcohols include:

• Polar nature, making them soluble in water.
• Distinct smell, often being pleasant or fruity in nature.
• Boiling points higher than hydrocarbons of a similar molecular weight due to hydrogen bonding.

Ethanol, a two-carbon alcohol with the formula C₂H₅OH, is a primary alcohol, one of the products in the hydrolysis of melissyl cerotate.
Ethanol is not only useful as a solvent and a biofuel but also plays key roles in various biochemical reactions, showcasing the broad utility and importance of alcohols in both industrial and biological contexts.