Can I paint oil based enamel paint over latex?

When it comes to a tough, high gloss finish, I think the oil base paints still have the edge. However, you could have problems over a latex. If it doesn't adhere right, it could still chip or even peel off in sheets. Roughening up the surface with sand paper might help. It may age poorly, eventually alligatoring. You might be safer with another latex. They are catching up on gloss and toughness.

This from somebody that once made his living on oil based paint.