- Phosphine-catalyzed tandem α-O-addition and transesterification of oxgen pronucleophiles on arylpropiolates: A new route to dioxygenated heterocyles
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A practical one step procedure for the synthesis of 1,4-di-oxane-2-one and 1,4-benzodioxine-2-one derivatives is described. Georg Thieme Verlag Stuttgart.
- Gabillet, Sandra,Lecercle, Delphine,Loreau, Olivier,Dezard, Sophie,Gomis, Jean-Marie,Taran, Frederic
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p. 515 - 522
(2008/01/03)
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- 1,3-Dipolar Cycloadditions of Ethoxycarbonyl-nitrile Benzylamine, and Synthesis of β-Amino Acids. Synthesis and Reactions of Ethyl 2-Chloro-2-ethoxyacetate and 2-Chloro-2-ethoxyacetyl Chloride
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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 synthesis 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 cyclization were carried out with the allylic ester - nitrile oxime and allylic ester - nitrile imine systems.
- Bach, Karen K.,El-Seedi, Hesham R.,Jensen, Henrik M.,Nielsen, Helene B.,Thomsen, Ib,Torssell, B. G.
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p. 7543 - 7556
(2007/10/02)
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