Abstract Glyoxylate and glycine or glycinamide react under moderately alkaline conditions even in the absence of metal ions to generate stable intermediates which absorb in the wavelength range 250–280 nm. The intermediates appear to be N -glyoxylylideneglycine and N -glyoxylylideneglycinamide. Carbanions, formed from these intermediates, react with glyoxylate to produce the aldol condensation products, β-hydroxyaspartic acid and β-hydroxyaspartamide. After reaction of glyoxylate and glycine in 3 H 2 O, tritium was found in glyoxylate, glycine, and β-hydroxyaspartic acid in a ratio of specific activity of 1:2:2. The formation of the β-hydroxyaspartic acids from glyoxylate and glycine was followed at pH 10.3, 25 °. The reaction reached completion at 50 hr after 18% of the reactants had condensed. The threo -β-hydroxyaspartic acid isomers composed 72% of the total. β-Hydroxyaspartamide formation from glyoxylate and glycinamide proceeded rapidly at pH 9.3 and 25 °, and 58% of the reactants were converted into β-hydroxyaspartamides after 6 hr. Transamination between glyoxylate and glycine occurred very slowly at pH 10.2 and 25 °. Complete exchange between glyoxylate and 1- 14 C-glycine required 25 days.