1,3-Dipolar cycloadditions of ethoxycarbonyl-nitrile benzylimine, EtOOC C N+ − N− CH2C6H5, and synthesis of β-amino acids. Synthesis and reactions of ethyl 2-chloro-2-ethoxyacetate and 2-chloro-2-ethoxyacetyl chloride
| Autor: | Kurt B. G. Torssell, I. Thomsen, Henrik Jeldtoft Jensen, Karen K. Bach, Hesham R. El-Seedi, Helene B. Nielsen |
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| Rok vydání: | 1994 |
| Předmět: |
chemistry.chemical_classification
Allylic rearrangement Nitrile organic chemicals Organic Chemistry Phosphonium salt Biochemistry Medicinal chemistry Nitrone chemistry.chemical_compound chemistry Drug Discovery 1 3-Dipolar cycloaddition Wittig reaction Organic chemistry Phosphonium Triphenylphosphine |
| Zdroj: | Tetrahedron. 50:7543-7556 |
| ISSN: | 0040-4020 |
| Popis: | The principles of 1,2-cyano-hydroxylation of olefins were applied to the preparation of 1,2-cyano-amines. The dipole component of this cycloaddition was nitrile imines, which formed pyrazolines with olefins. Ring cleavage was accomplished by thermolysis of 3-carboxypyrazolines, which gave 1,2-cyano-amines and subsequent hydrolysis gave β-amino acids. The syntheses of the title reagents were described. Ethyl 2-chloro-2-ethoxy-acetate gave selectively oximes, hydrazones, nitrones, and phosphonium salts with hydroxylamine, hydrazines, N -substituted hydroxylamines and triphenylphosphine respectively. The phosphonium salt was used in a Wittig reaction with aldehydes to give α-ketoesters. Treatment of the acid chloride with allyl alcohols and subsequently with a monosubstituted hydroxylamine gave the allylic ester nitrone, which underwent intramolecular cyclization. Similarly, intramolecular cyclizations were carried out with the allylic ester - nitrile oxide and allylic eater - nitrile imine systems. |
| Databáze: | OpenAIRE |
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