Abstract 5-Alkyl/aryl/hetaryl-4-cyano-3(2H)-furanones undergo ring-cleavage/recyclization in the presence of water under mild conditions [MOH (M = Na, K), aqueous ethanol, 20–25 °C] to afford 4-acyl/aroyl/hetaroyl-5-amino-3(2Н)-furanones in 75–99% yields. 5-Alkyl/aryl/hetaryl-4-cyano-3(2H)-furanones undergo ring-cleavage/recyclization in the presence of water under mild conditions [MOH (M = Na, K)
Amino acids (glycine, β-alanine, γ-aminobutyric and ε-aminocapronic acids, d,l-valine, and d,l-leucine) react under biomimetic conditions (H2O, NaOH, pH Ë8.6-9.9, room temperature) smoothly with α,β-acetylenic γ-hydroxyacid nitriles to give a novel family of unnatural amino acids containing a 5-imino-2,5-dihydro-3-furanyl substituent at the amino group, in 61-98% yield. As follows from a single-crystal X-ray analysis of 2-[(5-imino-2,2-dimethyl-2,5-dihydro-3-furanyl)amino]acetic acid, the synthesized amino acids are zwitterions with a protonated imino group in the iminodihydrofuran moiety.
molecules of cyanopropargylic alcohols under mild conditions (K2CO3, DMF, 20–25 °C, 10–48 h) by the hydroxy groups of the ribose moiety to afford representatives of the two novel families of cytidine cyclicketals. The first ones (53–76% yields) are formed with participation of the two vicinal hydroxyl groups (at 2′,3′-cis-positions) only. The second ones (7–21% yields) represent the adducts of cytidine with
摘要 胞苷通过核糖部分的羟基在温和的条件下(K 2 CO 3,DMF,20–25°C,10–48 h)与一个或两个氰基炔丙醇分子反应,以提供两个新的胞苷家族的代表环状缩酮。第一个(53-76%的收率)仅在两个邻羟基(2',3'-顺式位置)参与下形成。第二个(7-21%的收率)代表胞苷与两个涉及所有三个羟基的氰基炔丙醇分子的加合物。 胞苷通过核糖部分的羟基在温和的条件下(K 2 CO 3,DMF,20–25°C,10–48 h)与一个或两个氰基炔丙醇分子反应,以提供两个新的胞苷家族的代表环状缩酮。第一个(53-76%的收率)仅在两个邻羟基(2',3'-顺式位置)参与下形成。第二个(7-21%的收率)代表胞苷与两个涉及所有三个羟基的氰基炔丙醇分子的加合物。
Metal-free addition of aliphatic carboxylic acids to cyanopropargyl alcohols: an access to new families of functionalized dihydrofurans and 3(2H)-furanones
作者:Olesya A. Shemyakina、Olga G. Volostnykh、Anton V. Stepanov、Igor A. Ushakov、Anastasiya G. Malkina、Konstantin A. Apartsin、Viktoria V. Kireeva、Boris A. Trofimov
DOI:10.24820/ark.5550190.p010.569
日期:——
The metal-free Et3N-mediated addition of cyanopropargyl alcohols to aliphatic carboxylic acids provides for straightforward efficient access to 4-cyano-[(Z)-3-cyanomethylene]-2,3-dihydrofurans and 4-cyano-3(2H)furanones of pharmaceutical value. By comparison to analogous reactions using aromatic and heteroaromatic carboxylic acids, this synthesis is implemented under much milder conditions (room temperature
l-Tryptophan reacts with α,β-acetylenic γ-hydroxy nitriles, chemo- and regiospecifically, under mild, green conditions via a hydroamination-type process involving the primary amine group. The hydroxycyanopropanyl substituent of the initial adducts undergoes cyclization to afford a 2,5-dihydro-5-iminofuranyl moiety. Several novel amino acids are obtained in almost quantitative yields (95-98%), which exist