PURPOSE: To obtain the title compound having high stability, made possible in industrialization and useful for anticancer agent, etc., by reacting a specific thiophosphinic acid with a specific alcohol in the presence of a trityl salt or silver perchlorate.

CONSTITUTION: (A) A thiophosphinic acid ester derivative (bonded in acetal position) of 2-deoxyaldose obtained by substituting H of hydroxyl group of saccharide bonded with acetal in hemiacetal site of 2-deoxyaldose by a phosphinothioyl group expressed by the formula (R1 and R2 are alkyl or aryl) is reacted with (B) an alcohol selected from aliphatic alcohol, aromatic alcohol, steroid alcohol, glycerol derivative, saccharide derivative and amino acid derivative in the presence of (C) a trityl salt or silver perchlorate. Furthermore, dimethylthiophosphinic acid ester derivative is preferably used as the ingredient A.