Versatile synthons for optically pure alpha-amino aldehydes and alpha-amino acids: (+)- and (-)-4,5-dialkoxy-2-oxazolidinones.

Both enantiomers of trans-5-benzyloxy-4-methoxy- (BMOx) and trans-4,5-dimethoxy-2-oxazolidinones (DMOx), which are readily accessible from simple 2-oxazolone heterocycles, represent good candidates for a new class of chiral synthons for use in the preparation of optically pure alpha-amino aldehydes and alpha-amino acids, respectively.