Initial /wo/ to /ο/
Final /wo/ to /ω/
The glide /w/ is dropped.
wo-na-si | ὄνασι(ς) (onasis) (Doric) | advantage, profit, purchase
wo-na-si | ὤνησι(ς) (onesis) | advantage, profit, purchase
KN Gv 683 (Scribe unknown)
Cf. Onassis (Ωνάση), the name of the wealthy, merchant family.