Profpointy
Legendary Member
Acetone = propanone (C3)
MEK = butanone (C4)
You can put the position of the carbonyl in if you like and call them propan-2-one and butan-2-one but it's kind of redundant as there's nowhere else to put it. A carbonyl in the 1 position is an aldehyde.
Ah yes, can't be a 1 can it, and as you say, the 2 is redundant