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

Article abstract of DOI:10.1016/S0040-4020(01)90482-X

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.