Abstract: The present invention provides a glycoside derivative represented by the formula ##STR1## wherein G--O-- is a saccharide residue having no protective group, R is a hydrogen atom or a methyl group, m is 1 or 2, n is an integer of 1 to 4, and l is an integer of 1 or more provided that l.ltoreq.n; a polymer containing the glycoside derivative; a process for their preparation, and the use of the polymers.

Abstract: The present invention provides a glycoside derivative represented by the formula ##STR1## wherein G--O-- is a saccharide residue having no protective group, R is a hydrogen atom or a methyl group, m is 1 or 2, n is an integer of 1 to 4, and l is an integer of 1 or more provided that l.ltoreq.n; a polymer containing the glycoside derivative; a process for their preparation, and the use of the polymers.

Abstract: Disclosed are a glycosidation catalyst comprising at least one of heteropoly acids represented by the formulaH.sub.a X.sub.p M.sub.q O.sub.r .multidot.bH.sub.2 Owherein X is P, As, Si or Ge, M is at least one species selected from the group consisting of Mo, W and V, a is 3 4 or 6, b is an integer of 0 to 30, p is 1 or 2, q is 12 or 18, and r is 40 or 62, with the proviso that when X is P or As, a is 3 or 6; when X is Si or Ge, a is 4; and further (1) when X is P or As and a is 3, or when X is Si or Ge and a is 4, M is at least one species selected from the group consisting of Mo, W and V, p is 1, q is 12 and r is 40; and (2) when X is P or As and a is 6, M is Mo or W, p is 2, q is 18 and r is 62, and a process for preparing a glycoside derivative by using said catalyst.