TY - JOUR
T1 - 1,3-Dipolar cycloadditions of ethoxycarbonyl-nitrile benzylimine and synthesis of ß-amino acids. Synthesis and reactions of ethyl 2-chloro-2-ethoxyacetate and 2-chloro-2-ethoxyacetylchloride
AU - Bach, K.K.
AU - El-Seedi, H.R.
AU - Jensen, H.M.
AU - Nielsen, H.B.
AU - Thomsen, I.
AU - Torssell, K.B.G.
PY - 1994
Y1 - 1994
N2 - 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 beta-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 alpha-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 ester - nitrile imine systems.
AB - 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 beta-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 alpha-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 ester - nitrile imine systems.
U2 - 10.1016/S0040-4020(01)90482-X
DO - 10.1016/S0040-4020(01)90482-X
M3 - Journal article
SN - 0040-4020
VL - 50
SP - 7543
EP - 7556
JO - Tetrahedron
JF - Tetrahedron
IS - 25
ER -