Spontaneous resolution in the imidazolidin-2-one series

For the first time, spontaneous resolution of trans-dihydroxyimidazolidin-2-one 1a was performed and racemisation of (–)-1a was studied; regiospecific reaction of 1a–c with aminoguanidine resulted in derivatives 2a–c; compound 2b was also shown to undergo spontaneous resolution, and the absolute configuration (4R,5R) of (–)-2b crystals was established by X-ray diffraction analysis.