PURPOSE: To obtain protected mono-sugar and oligo sugar halides in a high yield with good selectivity, by using only a halogenating agent by reacting an anomeric hydroxyl group-containing protected sugar (deriv.) with secondary α-halogenoenamine in an inert solvent.

CONSTITUTION: On equivalent of protected sugar (deriv.) having an anomer hydroxyl group (A) is reacted with secondary α-halogenoenamine (pref., 1-chloro- N,N-2-trimethylpropenylamine) in an inert solvent (pref., THF) to halogenate an anomeric hydroxyl group of the compd. A to obtain the objective compd. having halogen of anomer. Reaction is pref. performed at high temp. up to 80°C after the compd. B is added to the inert solvent soln. of the compd. A at 0°C in a gas stream of a protective gas such as N2. As the compd. A, 2,3,4,6- tetra-O-acetylamannopyranose is pref.