Was the cave of Abraham in Shechem or Hebron?

Genesis 23:17–20 says: > So Ephron’s field in Machpelah near Mamre—both the field and the cave in it, and all the trees within the borders of the field—was deeded to Abraham as his property in the presence of all the Hittites who had come to the gate of the city. Afterward Abraham buried his wife Sarah in the cave in the field of **Machpelah** near **Mamre** (which is at **Hebron**) in the land of Canaan. So the field and the cave in it were deeded to Abraham by the Hittites as a burial site. (NIV) Acts 7:15–16 says: > Then Jacob went down to Egypt, where he and our ancestors died. > Their bodies were brought back to **Shechem** and placed in the tomb that > Abraham had bought from the sons of **Hamor** at **Shechem** for a certain sum > of money. (NIV) You may say that Jacob was simply buried in a different burial site. However, Genesis 50:12–14 clearly states otherwise: > So Jacob’s sons did as their father commanded. They carried his > body to the land of Canaan and buried it in the cave in the field of > **Machpelah** near **Mamre**. Abraham had bought this cave and field from > **Ephron the Hittite** to use as a burial place. After Joseph buried > his father, he returned to Egypt, along with his brothers and everyone > who had gone with him to bury his father. (NCV) It seems that both the location and the seller is off between the books. How can these passages be reconciled?