合成路线1

This compound can be prepared in two different ways: 1) The reaction of 1,4-dichloro-2-butene (I) with diethyl malonate (II) by means of sodium ethoxide in refluxing ethanol gives 1,1-bis(ethoxycarbonyl)-2-vinylcyclopropane (III), which by reaction with ammonia gas in DMF at 120 C is converted into 3-carboxamido-5-vinyl-2-pyrrolidone (IV). Finally, this compound is treated with concentrated HCl in refluxing acetic acid. 2) The treatment of (IV) with sodium ethoxide in refluxing ethanol gives 3-carboxy-5-vinyl-2-pyrrolidone (V), which is decarboxylated by treatment with refluxing acetic acid to afford 5-vinyl-2-pyrrolidone (VI). The bromination of (VI) with Br2 in CCl4 yields 5-(1,2-dibromoethyl)-2-pyrrolidone (VII), which by treatment with Na in liquid NH3 in a pressure vessel at 25 C is converted into 4-aminohex-5-inoic acid (VIII). Finally, this compound is partially reduced with H2 over a suitable catalyst.