| Abstract
| - The reactions of (2S)-2-amino-2-substituted-N-(4-nitrophenyl)acetamides 16a−c, succindialdehyde(13), and benzotriazole afforded enantiopure (3S,5R,7aR)-5-(1H-1,2,3-benzotriazol-1-yl)-3-substituted-1-(4-nitrophenyl)tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones 17a−c, which were converted bysodium borohydride into (3S,7aR)-3-substituted-1-(4-nitrophenyl)tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones 18a−c. Chiral (2S)-2-amino-2-substituted-N-(4-methylphenyl)acetamides 12a−d, easilyprepared in two steps from N-Boc-α-amino acids 10a−d, similarly reacted with glutaraldehyde(20) and benzotriazole to generate 5-benzotriazolyl-3-substituted-hexahydroimidazo[1,2-a]pyridin-2(3H)-ones 21a−d, which were converted by sodium borohydride directly into optically active3-substituted-hexahydroimidazo[1,2-a]pyridin-2(3H)-ones 22a−d.
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