Backdoor compared with the dominant in the chromatic circle. Note they share two tones and are transpositionally equivalent (by a m3). Resolutions, to a C major chord, marked with arrows.
<a href="//commons.wikimedia.org/wiki/User:Hyacinth" title="User:Hyacinth">Hyacinth</a>
<span class="int-own-work" lang="en">Own work</span>