Chemical and electrochemical oxidation of dienonic moiety of desmycosin were carried out. Successive chemical oxidation of desmycosin with m-chloroperbenzoic acid afforded a family of 12,13-dihydro-12,13-dihydroxy derivatives. Indirect electrochemical oxidation via hypobromite as an intermediate gave rise to the new bicyclo derivative of desmycosin, 13-hydroxy-3-dehydroxy-3,12-oxa-desmycosin.