H-(Aib)4-OEt | 500905-31-7

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: H-(Aib)4-OEt
• 英文别名: H-(Aib)₄-OEt
• CAS: 500905-31-7
• 化学式: C₁₈H₃₄N₄O₅
• 分子量: 386.492
• InChiKey: LZMKLQMPOAKTQN-UHFFFAOYSA-N

物化性质

• 沸点：
  617.0±55.0 °C(Predicted)
• 密度：
  1.101±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  -0.03
• 重原子数：
  27.0
• 可旋转键数：
  8.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.78
• 拓扑面积：
  139.62
• 氢给体数：
  4.0
• 氢受体数：
  6.0

反应信息

• 作为反应物：
  描述：

  (3R,4R)-3,4-diazido-1-(tert-butoxycarbonylamino)cyclopentanecarboxylic acid 、 H-(Aib)4-OEt 在 O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate 、 N,N-二异丙基乙胺 作用下， 以 乙腈 为溶剂， 反应 96.0h， 以68%的产率得到Boc-(R,R)-Ac₅c^dN3-(Aib)₄-OEt
  参考文献：
  名称：

  Conformational studies on peptides having chiral five-membered ring amino acid with two azido or triazole functional groups within the sequence of Aib residues

  摘要：

  The chiral cyclic alpha,alpha-disubstituted alpha-amino acid, (3R,4R)-1-amino-3,4-diazido-1-cyclopentanecarboxylic acid [(R,R)-Ac-5C(dN3)], was introduced into achiral alpha-aminoisobutyric acid (Aib) peptides. The azido groups of (R,R)-Ac-5C(dN3) in the peptides were efficiently converted into 1,2,3-triazole functional groups. FTIR, H-1 NMR, and CD spectra revealed that the dominant conformations of all peptides in solution were 3(10)-helical structures without controlling the helical-screw sense. X-ray crystallographic analyses of peptides containing (R,R)-Ac-5C(dN3) showed that both the right-handed (P) and left-handed (M) 3(10)-helical structures were present in the crystal state. (C) 2014 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2014.09.086
• 作为产物：
  描述：

  ethyl [(benzyloxy)carbonyl]-dimethylglycyl-dimethylglycyl-dimethylglycyl-dimethylglycinate 在 palladium on activated charcoal 氢气 作用下， 以 甲醇 为溶剂， 反应 16.0h， 生成 H-(Aib)4-OEt
  参考文献：
  名称：

  含有α-乙基化α，α-二取代氨基酸的杂五肽的构象研究：二甲基甘氨酸（=2-氨基异丁酸）残基序列中的（S）-丁基乙基甘氨酸（=2-氨基-2-乙基己酸）

  摘要：

  杂五肽含有 α-乙基化 α,α-二取代氨基酸 (S)-丁基乙基甘氨酸和四个二甲基甘氨酸残基，即 CF3CO-[(S)-Beg]-(Aib)4-OEt (4) 和 CF3CO-(Aib) 2-[(S)-Beg]-(Aib)2-OEt (7) 是通过常规溶液方法合成的。在固态下，4的优选构象显示为右手（P）和左手（M）310-螺旋结构，而7的优选构象是右手（P）310-螺旋结构结构体。IR、CD 和 1H-NMR 光谱显示溶液中 4 和 7 的主要构象是 310-螺旋结构。这些构象也得到了分子力学计算的支持。

  DOI：

  10.1002/1522-2675(20010131)84:1<32::aid-hlca32>3.0.co;2-4

文献信息

• Conformation of Peptides Containing a Chiral -Ethylated ,-Disubstituted -Amino Acid: (S)--Ethylleucine (=(2S)-2-Amino-2-ethyl-4-methylpentanoic Acid) within Sequences of Dimethylglycine and Diethylglycine Residues
  作者：Makoto Oba、Masakazu Tanaka、Masaaki Kurihara、Hiroshi Suemune

  DOI：10.1002/1522-2675(200210)85:10<3197::aid-hlca3197>3.0.co;2-y

  日期：2002.10

  An optically active (S)-alpha-ethylleucine ((S)-alphaEtLeu) as a chiral alpha-ethylated alpha,alpha-disubstituted alpha-amino acid was synthesized by means of a chiral acetal auxiliary of (R,R)-cyclohexane-1,2-diol. The chiral alpha-ethylated alpha,alpha-disubstituted amino acid (S)-alphaEtLeu was introduced into the peptides constructed from 2aminoisobutyric acid (= dimethylglycine, Aib), and also into the peptide prepared from diethylglycine (Deg). The X-ray crystallographic analysis revealed that both right-handed (P) and left-handed (M) 3(10)-helical structures exist in the solid state of CF3CO-(Aib)(2)-[(S)-alphaEtLeu]-(Aib)(2)-OEt (14) and CF3CO-[(S)-alphaEtLeu]-(Deg)(4)-OEt (18), respectively. The IR, CD, and H-1-NMR spectra indicated that the dominant conformation of pentapeptides 14 and CF3CO-[(S)-alphaEtLeu]-(Aib)(4)-OEt (16) in solution is a 3(10)-helical structure, and that of 18 in solution is a planar C-5 conformation. The conformation of peptides was also studied by molecular-mechanics calculations.