1,3-Dipolar cycloadditions of ethoxycarbonyl-nitrile benzylimine, EtOOC C  [formula omitted] − [formula omitted] CH 2C 6H 5, and synthesis of β-amino acids. Synthesis and reactions of ethyl 2-chloro-2-ethoxyacetate and 2-chloro-2-ethoxyacetyl chloride

Abstract

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.