Common name of the compound : `CH_(3)-CH=CH-overset(O)overset(||)(C)-OH` is -

Options

A. Crotonic acid
B. Acrylic acid
C. Allylic acid
D. None

Answer

To determine the common name of the compound `CH₃-CH=CH-C(=O)-OH`, we can follow these steps:

### Step 1: Identify the Functional Groups
The compound contains a carboxylic acid group (`-COOH`) and an alkene (`C=C`). The presence of both functional groups is crucial for naming.

**Hint:** Look for the highest priority functional group to determine the base name of the compound.

### Step 2: Determine the Longest Carbon Chain
Count the number of carbon atoms in the longest continuous chain that includes the carboxylic acid. In this case, the longest chain consists of four carbon atoms.

**Hint:** The longest chain should include the functional group with the highest priority.

### Step 3: Number the Carbon Chain
Number the carbon chain starting from the end nearest to the carboxylic acid group. This ensures that the carboxylic acid gets the lowest possible number.

**Hint:** Always give the functional group the lowest number when numbering the chain.

### Step 4: Identify the Alkene
The double bond is located between the second and third carbons of the chain. This indicates that the compound is an alkene.

**Hint:** The position of the double bond is indicated by the number of the first carbon involved in the double bond.

### Step 5: Combine the Names
The base name for a four-carbon carboxylic acid is "butanoic acid." However, due to the presence of the double bond, we modify the name to reflect this. The common name for this compound is "crotonic acid."

**Hint:** The common name often differs from the systematic IUPAC name, especially for well-known compounds.

### Final Answer
The common name of the compound `CH₃-CH=CH-C(=O)-OH` is **crotonic acid**.