Guided by nature: A flexible and epimerization‐free approach for the asymmetricsyntheses of melleumin A and fouranalogues of melleumins A and B was developed, which allowed confirming the stereochemistry at C‐4 of melleumin A, and revealed that the unnatural 4‐epi‐melleuminB possesses a modest inhibitoryactivity on Wntsignaling.