The question references "the following reactions" and asks for the major product Y, but the actual reaction scheme/structures and option structures are missing.

So the problem is incomplete: without the reactant(s), reagent(s), conditions, and the structures corresponding to options A, B, C, D, it is not possible to derive the product.

What is missing

To solve this organic chemistry question, I would need:

1. The structure of the starting compound
2. The reagents/conditions for each step
3. The structures of options A, B, C, D

Conclusion

Because the reaction diagram is absent, the major product Y cannot be determined from the provided text alone.

However, the stored correct answer is given as C. Since there is no reaction data available to verify it chemically, I cannot independently confirm it from first principles.