A chemical synthesis of DL-glyceraldehyde-3-phosphonic acid, the phosphonic acid analog of DL-glyceraldehyde-3-phosphoric acid, is reported. It was obtained from dimer DL-glyceraldehyde by two procedures differing solely in their protective groups via the following intermediates. Procedure 1: 2,5-diiodomethyl-3,6-dimethoxy-1,4-dioxane → 2,5-bis(methylphosphonic acid diethyl ester)-3,6-dimethoxy-1,4-dioxane → 2,5-bis(methylphosphonic acid)-3,6-dimethoxy-1,4-dioxane → DL-glyceraldehyde-3-phosphonic acid. Procedure 2: 2,5-bis(p-toluenesulfonyloxymethyl)-3,6-dibenzoxy-l,4-dioxane → 2,5-diiodomethyl-3,6-dibenzoxy-l,4-dioxane → 2,5-bis(methylphosphonic acid diethyl ester)-3,6-dibenzoxy-l,4-dioxane → 2,5-bis(methylphosphonicacid)-3,6-dibenzoxy-1,4-dioxane → DL-glyceraldehyde-3-phosphonic acid.