A 9-O-alkanoyl-3"-O-alkanoyloxymethyl-SF-837 substance is now synthetized, which is a new compound useful in that this new 9-O-alkanoyl-3"-O-alkanoyloxymethyl derivative of the SF-837 substance exhibits an antibacterial activity comparable to that of the parent SF-837 substance but is advantageously free from the unpleasant bitter taste inherent to the SF-837 substance and is hence adapted for oral administration. A process of producing the 9-O-alkanoyl-3"-O-alkanoyloxymethyl-SF-837 substance is also provided, which comprises hydrolysing partially and selectively a 9,2'-di-O-alkanoyl-3"-O-alkanoyloxymethyl-SF-837 substance in an aqueous alkanol or aqueous acetone. The 9,2'-di-O-alkanoyl-3"-O-alkanopyloxymethyl-SF-837 substance may be prepared by reacting a 9,2'-di-alkanoyl- or O-mono-O-alkanoyl-3"-O-thiomethoxymethyl-SF-837 substance with an alkanoic anhydride which is exemplified by acetic anhydride or propionic anhydride in the specification.