A novel galactosylmoranoline derivative represented by general formula (I), wherein R<1> represents optionally unsaturated C1-C18 acyl, aryloxycarbonyl, alkyloxycarbonyl or aralkyloxycarbonyl; R<2> represents hydroxy or acetamido; R<3> and R<4> differ from each other and represent hydroxy and 1-galactosyl respectively; and R<5> represents hydrogen or is combined with R<1> to represent carbonyl. The compound (I) is useful as a starting material for the enzymatic synthesis using fucosyltransferase of a sialyl Lewis sugar chain derivative which is a sugar chain antigen useful as a medicine.
