You can try to understand rotations in Red Black Trees in a better way by breaking down the operation into different rotations. There are only 3 basic operations for a Left Leaning Red Black BST. The operations are performed in order as listed in this slide.
Moreover, the Red Black Tree that you have shown is not correct as it violates the condition for a Red Black Tree. ie. Every path from the root to the leaf must have equal number of black edges. But in your final tree, the path from x to c has 2 black edges, while the path from x to a has 1 black edge. I recommend you to read more about self balancing BSTs and Red-Black BSTs from here.
PS. I do not own the slide. It has been taken from Robert Sedgewick's course on Algorithms from coursera.