Glycoaldehyde phosphate aldomerizes in aq. NaOH to a product mixt. contg. the racemates of two diastereomeric tetrose 2,4-diphosphates and 8 hexose 2,4,5-triphosphates. The aldomerization of glycoaldehyde in the presence of formaldehyde is a variant of the formose reaction. It avoids the formation of complex formose product mixts., because C(2)-phosphorylated aldoses cannot undergo aldose-ketose tautomerization. This work, with its demonstration of an intrinsic kinetic preference for ribose 2,4-diphosphate and allose 2,4,5-triphosphate formation, adds a piece of factual chem. information to ongoing discussion about the origin of ribonucleic acids. [on SciFinder (R)]