Javascript change object to custom array

I want to convert this object:

"age": [
  {
     "Under 20": "14",
     "Above 40": "1"
  }
]

to this: {c: [{v: Under 20}, {v: 14}], c: [{v: Above 40} {v: 1}]}

I know how to use $.map and arr.push but I can't get the key Under 20 and take the element value 14.

How can I achieve that?