global $wpdb,$post;
    $request = 'B';
    $results = $wpdb->get_results(
        "   SELECT * FROM $wpdb->posts
            WHERE post_title LIKE '$request%'
            AND post_type = 'product'
            AND post_status = 'publish';
        "
    );

  if ( $results ) {
        foreach ( $results as $post ) {
            setup_postdata ( $post ); ?>
                <li>
                    <?php echo $post->post_title; ?>
                </li>
           <?php
        }
    } else { ?>
    <div class="alert">No posts found for this particular letter.</div>
<?php }