structure–activity relationships, an analogue of bafilomycin A1 with a site-specific fluorine label at the C2 position was designed and efficiently synthesized. The fluorinated compound exhibited potent vacuolar-type ATPase (V-ATPase) inhibitoryactivity, comparable to that of the natural product, representing the first example of highly bioactive analogues with a modified macrolactone core from the plecomacrolide