Introduction:
The reaction of a mixture containing all the stereoisomers of 3, 4, 5-trimethyl cyclopentene with O3 followed by Zn-hydrolysis results in the formation of four different isomers of products. This can be explained based on the reaction mechanism and the stereochemistry of the starting material.

Reaction Mechanism:
The reaction starts with the ozonolysis of the cyclopentene double bond. Ozone (O3) reacts with the double bond to form an ozonide intermediate. This intermediate then undergoes a reductive workup with Zn-H2O to convert it into the products.

Stereochemistry of 3, 4, 5-trimethyl cyclopentene:
3, 4, 5-trimethyl cyclopentene is a chiral molecule with a stereocenter at the 3rd carbon atom. It exists as two enantiomers, designated as R and S, due to the presence of a chiral carbon atom. Each enantiomer can further exhibit cis-trans isomerism based on the relative positions of the methyl groups at the 4th and 5th carbon atoms.

Explanation:
When the mixture containing all the stereoisomers of 3, 4, 5-trimethyl cyclopentene undergoes ozonolysis, the ozonide intermediate is formed. This intermediate can undergo two different types of cleavage: oxidative cleavage and reductive cleavage.

1. Oxidative Cleavage:
In oxidative cleavage, the ozonide intermediate is cleaved to form two carbonyl compounds. This cleavage does not affect the stereochemistry of the starting material, and all the isomers will still be present in the products.

2. Reductive Cleavage:
In reductive cleavage, the ozonide intermediate is converted into aldehydes or ketones by the addition of Zn-H2O. This step can lead to changes in the stereochemistry of the starting material.

Different Isomers of Products:
The four different isomers of the products can be obtained based on the possible combinations of the stereochemistry of the starting material and the reductive cleavage.

1. R-R isomer: This isomer is obtained when the R-enantiomer of 3, 4, 5-trimethyl cyclopentene undergoes reductive cleavage. The resulting products will retain the R configuration at the stereocenter.

2. R-S isomer: This isomer is obtained when the R-enantiomer of 3, 4, 5-trimethyl cyclopentene undergoes reductive cleavage. The resulting products will have the S configuration at the stereocenter.

3. S-R isomer: This isomer is obtained when the S-enantiomer of 3, 4, 5-trimethyl cyclopentene undergoes reductive cleavage. The resulting products will have the R configuration at the stereocenter.

4. S-S isomer: This isomer is obtained when the S-enantiomer of 3, 4, 5-trimethyl cyclopentene undergoes reductive cleavage. The resulting products will retain the S configuration at the stereocenter.

Therefore, the reaction of the mixture containing

4 is correct.