The liquid vowel “i” in ancient Greek and Latin often becomes a consonantal “j” in English: “Jason” for “Iason,” “Jesus” for “Iesus,” “Julius,” “Juno,” “juvenile,” etc. The French have Troyen and Troyenne; in German it’s Trojaner but pronounced “Troy-ahner.” It’s the same “y” sound in Italian and Spanish. The Portuguese spell and say it a bit like us, though: Trojan to rhyme with “explosion.” Modern Greeks say Tro-as, rhyming with “slow ass.”