New synthetic routes to β-fluoro-α-aminoacids A - from aziridinecarboxylates

Synthesis of 1-trityl-2-phenylaziridine, 1-trityl-2-methylaziridine and 2-methylcarboxylates of 1-tritylaziridine, 1-trityl-3-methylaziridine, 1-trityl-3-phenylaziridine by reacting N-triphenylmethyl-α-chloroamines with KF in acetonitrile under reflux is described.Functionalized aziridines opened with hydrogen fluoride in pyridine (70 %) give isobutyl 3-fluoroalanine, methyl-3-fluorophenylalanine and methyl 2-amino-3-fluorobutyrate.N.M.R. ¹H and ¹⁹F are discussed.The following reactions get the compounds in the table.