Exegesis:

elaiō tēn kephalēn mou ouk ēleipsas ‘with olive oil you did not anoint my head.’ elaiō is emphatic. The anointing of the head was a gesture of hospitality. Cf. also on v. 38. There is a twofold correspondence between this clause and the next, i.e. elaiō and murō, a cheap and a very expensive unguent, and kephalēn and podas, the usual spot of anointing and a rather unusual one.

Translation:

You did not anoint my head with oil, or, better to bring out the pejorative connotation, “you did not anoint my head, even with oil” (The Four Gospels – a New Translation); or, again making explicit the function, ‘you didn’t show me hospitality (or, give me a reception) by anointing my head.’ The host usually did the anointing himself.

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.