A number of 6-O-ether and 4-O-ether derivatives of mannopeptimycin-alpha with different steric bulk and lipophilicity were synthesized for structure-activity relationship study. Novel iodo and bromo mannopeptimycin-alpha were also prepared. These compounds were synthesized via electrophilic aromatic substitution. Many of the new ether derivatives exhibited potent antibacterial activity against Gram-positive resistant strains including VRE, MRSA, and PRSP.