What is the problem with forming 2,3-dimethylcyclohex-2-en-1-one?
Your starting product for A is symmetrical, but your starting product for B will be asymmetrical - one carbon less on one side.  This is going to mean you may get 2 or more different products; B may not be your major product, and you'll have to separate them afterwards.  I don't believe there's inherently a tricky difficultly in the mechanism for B.