Provided are macrolide compounds for the treatment of infectious diseases. The macrolides disclosed herein include 14-membered ketolides and 14-15-membered azaketolides, and may comprise modified sugars which are desosamine analogues. The disclosed macrolides may have a bicyclic structure. Also provided are pharmaceutical compositions and methods of treating infectious diseases, and in particular, disease which results from Gram negative bacteria using the disclosed macrolides. This disclosure additionally provides methods of preparing the macrolides by a strategy that enables late-stage modification of the 6′-position of the sugar moiety, thereby allowing facile access to previously difficult-to-make macrolide compounds.