Diagonal Rotation On Pivot with animation doesn't work correctly

I have a 2D sprite and i am trying to rotate it in such a way that it look like a paper fold. But while rotating it in diagonal and making its animation , i am having some abnormal rotation in results .
Here is the video of me rotating the sprite (corner of page) through inspector

and after this i am trying to create an animation by simply recording it through animation.


These are the rotation values

Result

Thank you in advance