REACTIVE PHOSPHONIC-ACIDS AS PREBIOTIC CARRIERS OF PHOSPHORUS

Phosphonic acids are the only phosphorus-containing organic compounds detected in the Murchison meteorite. We earlier described the synthesi s of methyl-, hydroxymethyl-, and 1-hydroxyethyl phosphonic acids usin g sodium phosphite as a source of phosphite radicals. We now show that ultraviolet irradiation of dilute aqueous solutions of acetylene in t he presence of sodium phosphite leads to the synthesis of vinyl phosph onic acid. At neutral to basic pH, vinyl phosphonic acid reacts under photochemical conditions to produce phosphonoacetaldehyde and 2-hydrox yethyl phosphonic acid as the major products, as well as smaller yield s of l-hydroxyethyl phosphonic acid, phosphonoacetic acid, and ethyl p hosphonic acid. Of these products, phosphonoacetaldehyde is particular ly interesting as a potential precursor of prebiotic carbohydrate deri vatives.