How to redirect non admins to homepage if trying to view mysite.com/wp-admin/?

I been using this code for a while I think it was originaly on a plugin called wp block admin but this works. You just have tho change the required compatibility so that it does what you need, look at this

$required_capability = 'edit_others_posts';
$redirect_to = '';
function no_admin_init() {      
    // We need the config vars inside the function
    global $required_capability, $redirect_to;      
    // Is this the admin interface?
    if (
        // Look for the presence of /wp-admin/ in the url
        stripos($_SERVER['REQUEST_URI'],'/wp-admin/') !== false
        &&
        // Allow calls to async-upload.php
        stripos($_SERVER['REQUEST_URI'],'async-upload.php') == false
        &&
        // Allow calls to admin-ajax.php
        stripos($_SERVER['REQUEST_URI'],'admin-ajax.php') == false
    ) {         
        // Does the current user fail the required capability level?
        if (!current_user_can($required_capability)) {              
            if ($redirect_to == '') { $redirect_to = get_option('home'); }              
            // Send a temporary redirect
            wp_redirect($redirect_to,302);              
        }           
    }       
}
// Add the action with maximum priority
add_action('init','no_admin_init',0);