Write IUPAC names of the products obtained by the ozonolysis of the following compounds:
(i) Pent-2-ene (ii) 3,4-Dimethyl-hept-3-ene
(iii) 2-Ethylbut-1-ene (iv) 1-Phenylbut-1-ene

Explanation

To determine the IUPAC names of the products obtained by the ozonolysis of the given compounds, we will follow these steps for each compound:

### (i) Pent-2-ene
1. **Draw the structure**: Pent-2-ene has a double bond between the second and third carbon atoms. The structure is:
```
CH3-CH=CH-CH2-CH3
```
2. **Ozonolysis**: Ozone (O3) will react with the double bond, forming an ozonide. The ozonide structure will look like:
```
CH3-CH(O)-CH(O)-CH2-CH3
```
3. **Hydrolysis**: The ozonide is then hydrolyzed (usually in the presence of zinc), resulting in the cleavage of the carbon-carbon bond and formation of two aldehydes:
- CH3CHO (ethanal)
- CH3CH2CHO (propanal)
4. **IUPAC names**: The products are:
- Ethanal (acetaldehyde)
- Propanal

### (ii) 3,4-Dimethylhept-3-ene
1. **Draw the structure**: The structure has a double bond at the third carbon and two methyl groups on the third and fourth carbons:
```
CH3-CH(CH3)-C=CH-CH2-CH(CH3)-CH3
```
2. **Ozonolysis**: The double bond will react with ozone, forming an ozonide:
```
CH3-CH(CH3)-C(O)-C(O)-CH2-CH(CH3)-CH3
```
3. **Hydrolysis**: Hydrolysis will yield:
- CH3-CH(CH3)-C(O)-H (3-methylbutanal)
- CH3-CH2-C(O)-CH3 (butan-2-one)
4. **IUPAC names**: The products are:
- 3-Methylbutanal
- Butan-2-one

### (iii) 2-Ethylbut-1-ene
1. **Draw the structure**: The structure has a double bond at the first carbon and an ethyl group at the second carbon:
```
CH2=CH-CH2-CH(CH2CH3)-CH3
```
2. **Ozonolysis**: The ozonide formation will occur:
```
CH2(O)-C(O)-CH2-CH(CH2CH3)-CH3
```
3. **Hydrolysis**: Hydrolysis will yield:
- CH3-CH2-CHO (butanal)
- CH3-CH2-CH2-C(O)-H (pentanal)
4. **IUPAC names**: The products are:
- Butanal
- Pentanal

### (iv) 1-Phenylbut-1-ene
1. **Draw the structure**: The structure has a double bond at the first carbon and a phenyl group:
```
C6H5-CH=CH-CH2-CH3
```
2. **Ozonolysis**: The ozonide formation will occur:
```
C6H5-CH(O)-C(O)-CH2-CH3
```
3. **Hydrolysis**: Hydrolysis will yield:
- C6H5CHO (benzaldehyde)
- CH3-CH2-C(O)-H (butanal)
4. **IUPAC names**: The products are:
- Benzaldehyde
- Butanal

### Summary of IUPAC Names of Products:
1. **Pent-2-ene**: Ethanal and Propanal
2. **3,4-Dimethylhept-3-ene**: 3-Methylbutanal and Butan-2-one
3. **2-Ethylbut-1-ene**: Butanal and Pentanal
4. **1-Phenylbut-1-ene**: Benzaldehyde and Butanal