Synthesis of Glycosylrifamycins, a new type of semisynthetic rifamycins

Glycosylrifamycins, a new type of semisynthetic rifamycin derivatives, can be easily obtained by reaction of 3‐(2‐aminoethylthio)rifamycin SV ( 2 ) with a glycosyl compound carrying a coupling group, such as isothicyanate or carboxy. We prepared O ‐acetylated and free glucopyranosyl and arabinopyranosyl derivatives of rifamycin S and SV (see 3–10 ). Additionally, derivatives with D ‐saccharo‐1,4‐lactone and with shikimic acid were obtained (see 11–15 ). Glycosylrifamycins show an interesting inhibitory power on Gram ‐positive bacteria ( Table ).