N, N-Phthaloyl-1-bromo-3, 4, 6-tri-O-acetyl-1-deoxy-β-D-glucosamine (III) reported in Part IV¹⁾ of this series is the first example of 1, 2-trans-acetobromo-sugar obtained in glucose and glucosamine series. Several replacement reactions at C-1 position of (III) as well as properties of several new N, N-phthaloyl derivatives of D-glucosamine were described in the present paper. From the results of these reactions, it was concluded that the replacement reaction at C-1 position of N, N-phthaloyl derivatives of D-glucosamine gave β-anomers and there was some steric hinderance for the formation of α-anomers.