alpha,beta-Didehydroglutamates have been diastereoselectively transformed into 6-oxoperhydropyridazine-3-carboxylic acid derivatives (OPCAs), which constitute a new class of cyclic amino acid derivatives. Acylation at N-1 renders dipeptides which show considerable conformational rigidity. Semiempirical calculations suggest that OPCAs might force peptide turns with different amplitudes depending on
α,β-Didehydroglutamate已被非对映选择性地转化为6-氧杂氢
哒嗪-3-
羧酸衍
生物(OPCA),这构成了一类新的环状
氨基酸衍
生物。N-1的酰化作用使二肽显示出相当的构象刚度。半经验计算表明,OPCAs可能会根据取代模式和
哒嗪酮环取代基的相对立体
化学作用,迫使肽以不同的幅度旋转。