Although there is no built-in feature allowing you to undo an iPhone sync, you can do so by restoring a previous backup. ITunes maintains your old backups indefinitely, so all you have to do is identify which backup you made prior to the most recent sync and then restore that one. In effect, this will undo the sync and restore the iPhone to the state is was in previously. Unfortunately, if you don’t have a prior backup to restore, you won’t be able to undo the sync. Writer Bio
