after selesction of the permanent protecting groups, the number of the temporary protecting groups is dependent on the structure of the target molecule. in the case of of a branched oligosaccharide numerous temporary groups are necessary that must be selectively removable in the presence of each other (orthogonal. the permanent and temporary protecting groups are not nescessarily the membersof another type of compounds. in oligosaccharide syntheses,benzoate esters are often used as permanent groups togenther with the selectively removable acetate or chloracetate esters as temporary protecting groups.