Hope this answer isn't too late. However ionic 2 now supports the splitplane that works exactly as you described. Its syntax is as:

<ion-split-pane>
  <!--  our side menu  -->
  <ion-menu [content]="content">
    <ion-header>
      <ion-toolbar>
        <ion-title>Menu</ion-title>
      </ion-toolbar>
    </ion-header>
  </ion-menu>

  <!-- the main content -->
  <ion-nav [root]="root" main #content></ion-nav>
</ion-split-pane>