Dehydroamino acid (Dhaa) is recognized as a useful tool or substrate for amino acid and peptide research. Although the stereoselective synthesis of the thermodynamically more stable Z-Dhaa has been well examined and established, the stereoselective synthesis of E-Dhaa has still remained to be a challenging synthetic task. In this paper, a stereoselective synthesis of E-Dhaa esters using a new (α-d
脱氢氨基酸 (Dhaa) 被认为是氨基酸和肽研究的有用工具或底物。尽管热力学上更稳定的 Z-Dhaa 的立体选择性合成已得到充分研究和确立,但 E-Dhaa 的立体选择性合成仍然是一项具有挑战性的合成任务。在本文中,描述了使用新的(α-二苯基膦酰基)甘氨酸立体选择性合成 E-Dhaa 酯。新方法的特征方面总结如下:(i)金属添加剂在促进 E 立体选择性方面起着重要作用。(ii) NaI 用于合成带有芳基取代基和氨基官能团的 E-Dhaas,
Syntheses of 2-[(1<i>S</i>,3<i>S</i>)-1-Amino-3-carboxy-3-hydroxypropyl]thiazole-4-carboxylic Acid and the Tripeptide Skeleton of Nosiheptide Containing the Acid
The stereoselective synthesis of an amino acid component called Fragment D, N,O-diprotected 2-[(1S,3S)-1-amino-3-carboxy-3-hydroxypropyl]thiazole-4-carboxylic acid of a macrobicyclic peptide antibiotic nosiheptide, was achieved by two routes. The dipeptide, Fragment B-C, 2-[(Z)-1-(N,O-isopropylidene-L-threonylamino)-1-propenyl]thiazole-4-carboxylic acid was also synthesized by the thiazole ring formation
1,3-Dipolar Cycloadditions of Diazomethane to Chiral Electron-Deficient Olefins: The Origin of the π-Facial Diastereoselection
作者:Elena Muray、Angel Alvarez-Larena、Joan F. Piniella、Vicenç Branchadell、Rosa M. Ortuño
DOI:10.1021/jo991227j
日期:2000.1.1
The stereochemical outcome of diazomethane cycloadditions to several chiral electron-deficientolefins has been investigated in order to establish the origin of the pi-facial diastereoselection. Nitro olefins, vinyl sulfones, enoates, and 2-amino enoates have been used for such a purpose. These substrates have been prepared from D-glyceraldehyde acetonide through Wittig-type condensations and present
Synthesis and photochemical decomposition of pyrazolines from homochiral amino pentenoates. A laser flash-photolysis study
作者:JoséM. Jiménez、JoséL. Bourdelande、Rosa M. Ortuño
DOI:10.1016/s0040-4020(97)00098-7
日期:1997.3
order to find the optimal conditions and to establish the influence of sensitizers. The transient behaviour of the pyrazoline triplet state has been analyzed by laser flash photolysis either after direct excitation or after energy transfer from benzophenone.