How can I stop a function encoding an entity?

I use the code below in my functions to pre-populate new posts.

It works fine, except if I use entities (example: »), which are converted (example: ») when I open the edit page for a new post.

I prefer to keep them unconverted.

    add_filter( 'default_content', 'pu_default_editor_content' );

    function pu_default_editor_content( $content ) {
    global $post_type;
    switch( $post_type )
    {
    case 'post':
    $content = 'Default content for blog posts.';
    break;
    }
    return $content;
    }