Sorry , im not sure what ladder jump you mean. In the purple cave, go down ,then right. Talk to the lady.
Then go right,up,up, .... left to the armor...,left,up,right.
Drop down and go right across the top of the rooms back the way you came. Then up the other ladder. Then you should be next to the boss room and it should save there.
I posted a cheat map on the wip page .