While for the present invention one employs an amine of the structure YNH.sub.2 and D-glyceraldehyde or isopropyledene-D-glyceraldehyde, it will be appreciated that any amine such as ammonia, a primary or secondary amine, or anitrogen-containing heterocycle of the structure ##EQU1## can be reductively alkylated with the selected glyceraldehyde by the novel method of this invention.It is sometimes