The IUPAC name of given compound is :-
`CH_(3) - C -= C - undersetunderset(CH_(3))(|)oversetoverset(CH_(3))(|)C-CH_(3)`

Options

A. methyl tertiarybutyl acetylene
B. t-Butyl propyne
C. 4,4-Dimethyl-2-pentyne
D. 1,3,3,3-Tetramethyl ethyne

Answer

To determine the IUPAC name of the given compound, we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
- The first step in IUPAC naming is to identify the longest continuous carbon chain in the compound. In this case, the longest chain consists of 5 carbon atoms.

### Step 2: Determine the Parent Chain Name
- The parent chain with 5 carbon atoms is called "pentane." However, since the compound contains a triple bond, we need to change the suffix from "ane" to "yne." Therefore, the base name becomes "pentyne."

### Step 3: Identify the Type of Bond
- Since the compound has a triple bond, it is classified as an alkyne.

### Step 4: Number the Carbon Chain
- We need to number the carbon chain to indicate the position of the triple bond. We will start numbering from the end of the chain closest to the triple bond to give it the lowest possible number.
- Numbering from left to right, we get:
- 1 (C1) - 2 (C2) - 3 (C3) - 4 (C4) - 5 (C5).
- The triple bond is located between C2 and C3.

### Step 5: Determine the Position of the Triple Bond
- The position of the triple bond is on the second carbon atom. Thus, we denote this as "2-pentyne."

### Step 6: Identify and Name the Substituents
- The compound has two methyl groups (–CH₃) attached to the fourth carbon.
- Since there are two identical substituents, we use the prefix "di" to indicate this.

### Step 7: Determine the Position of the Substituents
- The methyl groups are located on the 4th carbon, so we denote this as "4,4-dimethyl."

### Step 8: Combine the Names
- The final IUPAC name is constructed by placing the substituent names before the parent name. Therefore, the complete name is "4,4-dimethyl-2-pentyne."

### Final Answer
The IUPAC name of the given compound is **4,4-dimethyl-2-pentyne**.

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