Seems to me that ko at is the best White can hope for given that White is split into two groups in the corner and one of those groups has only two liberties.
Tapir: White takes first. (Corr. ed.) Reading to the ko is often quite easy, but what type of ko, how many approach moves etc. I always make mistakes with that, a pity.
This doesn't work, right?
unkx80: A bit nit-picky, but can be at to save those three stones.