Parashat Hayye Sarah describes Abraham's purchase of the Cave of Machpelah from Ephron, who is a member of a group collectively referred to as "The Hittites" or "Children of Heth."
It is currently popular among scholars to dismiss this narrative as an anachronism and to claim that no Hittites dwelled in Canaan during Patriarchal times.
However, a little bit of research reveals that this difficulty was created by the scholars themselves. The suggestion was first made (by some) to identify the Hittites in our Parasha with a specific kingdom that existed in Biblical times. It was subsequently discovered that these alleged "Hittites" did not migrate to Israel until long after Abraham's lifetime. The conclusion was then drawn that the Hittite presence in Canaan, described in Hayye Sarah, cannot possibly reflect historical reality.
The link above demonstrates that the various scholarly hypotheses about the identity of the Hittites are inconclusive at best (for more details, consult Nahum Sarna's 19th Excursus in the JPS Commentary on Genesis.). In fact, there were (and are) legitimate approaches to this issue that pose no problem for the Torah's account. So there is no basis here for questioning the Tanach's historicity.
In the arena of Biblical studies, there is a marked tendency to cry "anachronism" prematurely, based on the latest unsupported scholarly conjecture. This happened with regard to the identification of Ur and the Phillistines, as well as with regard to the existence of domesticated camels in Patriarchal times.
The lesson to be learned here is that our ability to accurately reconstruct the past is limited, and that even scientific-sounding conclusions about the realities of the ancient world are always somewhat tentative.