How many of the following compounds can be categorized as allylic halides? 3-Chloropropene, 3 -bromocyclohexene, benzyl chloride, 4 -iodopent- 2 -ene, bromobenzene, (1-chloroethyl)benzene, 4 -chlorocyclopentene, 1-chlorobut-1-ene, 1-chlorobut-2-ene1345

Allylic halides are compounds in which a halogen atom is bonded to an allylic carbon. An allylic carbon is a carbon atom adjacent to a carbon-carbon double bond.

Let's go through each compound:

1. 3-Chloropropene: This is an allylic halide because the chlorine is bonded to the carbon adjacent to the carbon-carbon double bond.

2. 3 -bromocyclohexene: This is an allylic halide because the bromine is bonded to the carbon adjacent to the carbon-carbon double bond.

3. Benzyl chloride: This is an allylic halide because the chlorine is bonded to the carbon adjacent to the carbon-carbon double bond.

4. 4 -iodopent- 2 -ene: This is not an allylic halide because the iodine is not bonded to a carbon adjacent to a carbon-carbon double bond.

5. Bromobenzene: This is not an allylic halide because the bromine is not bonded to a carbon adjacent to a carbon-carbon double bond.

6. (1-chloroethyl)benzene: This is not an allylic halide because the chlorine is not bonded to a carbon adjacent to a carbon-carbon double bond.

7. 4 -chlorocyclopentene: This is an allylic halide because the chlorine is bonded to the carbon adjacent to the carbon-carbon double bond.

8. 1-chlorobut-1-ene: This is not an allylic halide because the chlorine is bonded to a carbon involved in a carbon-carbon double bond, not adjacent to it.

9. 1-chlorobut-2-ene: This is an allylic halide because the chlorine is bonded to the carbon adjacent to the carbon-carbon double bond.

So, out of the 9 compounds listed, 5 can be categorized as allylic halides.