Synthesis and aggregation of a 5-hydroxy-2,5-dihydropyrrole. Enantiomerically pure, one-dimensional strands via hydrogen bonds and chiroselective self organization [1]

Reaction of dimethyl 1,3-acetonedicarboxylate 8 with oxalylchloride 2 and m agnesium chloride as catalyst yielded 2,3-dioxo-2,3-dihydrofuran 9, which i s in equilibrium with tautomer 10 (9:10 = 1:2). Addition of thionyl chlorid e to a mixture of 9/10 afforded 3-chloro-2(5H)-furanone 11. The structure o f 11 was unequivocally established by X-ray diffraction, which indirectly p roved the structure of 10 as well. Ring opening of 11 by nucleophilic attac k with benzylamine 14 in C2-position and subsequent recyclization led to ra cemic 3-chloro-5-hydroxy-2-oxo-2,5-dihydropyrrole 15. According to a single crystal X-ray analysis, 15 aggregates via stereospecific self selection th rough hydrogen bonds to give chiroselectively the one-dimensional strands ( 1)(infinity)[(S)-15] and (1)(infinity)[(R)-15].