Enemy spawning problem

i have an enemy which when crosses a point on the x i destroy it. This is the script: if(enemy.transform.position.x<=-4.7){ Destroy(enemy); DestructiveScript.des -= 1; }

Also when the enemy crosses a point i instantiate it. This is the script:

if (enemy.transform.position.x >= st && enemy.transform.position.x <= en && and) { Instantiate(enemy); DestructiveScript.des += 1; }

When there are no enemies in the game i want to instantiate a enemy. This is the script:

public GameObject enemy; public static int des = 1; void Start () {

 }
 
 // Update is called once per frame
 void Update () {
     if(des==0){
         Instantiate(enemy);
     }
 }

Problem is that when the last enemy is so called destroyed , it generates the enemy but generates it just where the previous enemy died even though i have a script that should spawn it somewhere else.

Here is that script:

 public class enemyscript : MonoBehaviour {
 public GameObject enemy;
 public Text score;
 int abc=1;
 public float speed;
 private Vector3 one = new Vector3(4.5f, 0.6f, 0f);
 private Vector3 two = new Vector3(4.5f, 0.6f, 1f);
 private Vector3 three = new Vector3(4.5f, 0.6f, 2f);
 private Vector3 four = new Vector3(4.5f, 0.6f, -1f);
 private Vector3 five = new Vector3(4.5f, 0.6f, -2f);
 public Vector3 store;
 public float st;
 public float en;
 private int i = 0;
 bool xc = true;
 Vector3 forwardRotationPoint;
 Vector3 backRotationPoint;
 Vector3 leftRotationPoint;
 Vector3 rightRotationPoint;
 Bounds bounds;
 bool rolling;
 bool and = true;
 int a;
 int lolipop;
 private long dodgefrog;
 double valuOfScore = 0;

 bool isThere = false;
 void Start()
 {
     lolipop = 1;
     dodgefrog = 0;
     store = Gen(store);
     enemy.transform.position = store;
     bounds = GetComponent<MeshRenderer>().bounds;
     forwardRotationPoint = new Vector3(0, -bounds.extents.y, bounds.extents.z);
     backRotationPoint = new Vector3(0, -bounds.extents.y, -bounds.extents.z);
     leftRotationPoint = new Vector3(-bounds.extents.x, -bounds.extents.y, 0);
     rightRotationPoint = new Vector3(bounds.extents.x, -bounds.extents.y, 0);

 }
 private void OnCollisionEnter(Collision collision)
 {
     if(collision.gameObject.name.Equals("playerdup")){
         Time.timeScale = 0;


     }
 }
 void Update()

 {
    
     
     
     if(enemy.transform.position.x<=-4.7){
         Destroy(enemy);
         scorecontroller.scorevalue += 1;
         DestructiveScript.des -= 1;
         lolipop-=1;
         isThere = true;



     }



     
     //if (iii == 0&&isThere)
     //{
     //    iii++;
     //    Instantiate(enemy);
     //    Debug.Log("Extra" + iii);

     //}





     if (enemy.transform.position.x >= st && enemy.transform.position.x <= en && and)
     {
         Instantiate(enemy);
         lolipop += 1;
         DestructiveScript.des += 1;

         and = false;
     }

     if(lolipop==0){
         Instantiate(enemy);

     }

     if (rolling)
         return;



     StartCoroutine(Roll(leftRotationPoint));

 }

 private IEnumerator Roll(Vector3 rotationPoint)
 {
     Vector3 point = transform.position + rotationPoint;
     Vector3 axis = Vector3.Cross(Vector3.up, rotationPoint).normalized;
     float angle = 90;
     float a = 0;

     rolling = true;
     and = true;
     while (angle > 0)
     {
         a = Time.deltaTime * speed;
         transform.RotateAround(point, axis, a);
         angle -= a;
         yield return null;
     }

     transform.RotateAround(point, axis, angle);

     rolling = false;




 }
 public Vector3 Gen(Vector3 sam)
 {
     int posStart = Random.Range(0, 5);
     if (posStart == 0)
     {

         sam = one;
     }
     else if (posStart == 1)
     {

         sam = two;
     }
     else if (posStart == 2)
     {

         sam = three;
     }
     else if (posStart == 3)
     {
         sam = four;
     }
     else if (posStart == 4)
     {
         sam = five;
     }
     return sam;
 }

Any help would definitely be appreciated Thanks