Move a div somewhere else in the dom

The following code gets dynamically inserted into the DOM. However, I'd like to move div#example from where it is and prepend it to #wrapper. How can I use jQuery to achieve this?

<div id="wrapper">
     <div id="div1">
          <div id="example">
          </div>
     </div>
     <div id="div2">

     </div>
</div>

I tried $('#wrapper').prepend('#example');

But that just adds the text #example (not the div) into #wrapper.