How to execute a String code in the form of StandardForm?

I want to get execution results for strings of various forms. For this, I used ToExpression.

    case1 = ToExpression["(1/2)^3"]
    case2 = ToExpression["\!\(\*SuperscriptBox[FractionBox[\(1\), \(2\)], \(3\)]\)"]
    case3 = ToExpression["(\!\(\*FractionBox[\(1\), \(2\)]\)\!\(\*SuperscriptBox[\()\), \\(3\)]\)"]

[![enter image description here][1]][1]

As a result of execution, Case 3 did not get the result I wanted. How can I solve it?


  [1]: https://i.sstatic.net/dHaT6.png