Versatile chiral synthons for 1,2-diamines: (4S,5S)- and (4R,5R)-4,5-dimethoxy-2-imidazolidinones

(4S,5S)- and (4R,5R)-1-Acyl-4,5-dimethoxy-2-imidazolidinone derivatives, which are readily accessible from simple 1,3-dihydro-2-imidazolone heterocycles, represent good candidates for a new class of chiral synthons for use in the preparation of optically active threo-diamines such as 2S,3R- and 3S,4S-diamino carboxylic acids.