Syntheses of dl-isoserine (3-amino-2-hydroxypropanoic acid, 7) and further functionalized derivatives are described. Reaction of glyoxylic acid with nitromethane gives the known 2- hydroxy-3-nitropropanoic acid (8), which upon hydrogenolysis affords dl-isoserine in high yield. The comparable nitro-aldol reaction of 3-nitropropanal ethylene acetal (2) with glyoxylic acid produces 2-hydroxy-3-nitro-5-oxopentanoic acid ethylene acetal (4a) as a ...
