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[摘要]：The reaction of prolinamine derivatives (8a,b) and dialkyl dicyanofumarates (1) in dichloromethane at room temperature leads to the optically active enamines (10). Whereas products (10) in the case of 1-benzyl prolinamine (8a) are stable compounds, the corresponding enamines obtained from the non-protected prolinamine (8b) smoothly undergo a cyclocondensation at room temperature to give perhydropyrrolo[1,2-a]pyrazine derivatives (11). The molecular structure of 11a was established by X-Ray crystallography. In analogy to 8a, 1-benzyl prolinehydrazide (9a) and 1b in dichloromethane react to yield the enehydrazine (12b). On the other hand, the reaction of 9a and 1 in methanol at room temperature leads to the corresponding dialkyl 3-amino-1H-pyrazole-4,5-dicarboxylates (13) and methyl 1-benzylprolinate (14b) via a stepwise mechanism. The analogous reaction was observed between a 3-oxidoimidazole-4-carbohydrazide (15) and 1b. |
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