A convenient synthesis of aziridine-2-carboxylic esters
作者:Johan Legters、Lambertus Thijs、Binne Zwanenburg
DOI:10.1002/recl.19921110101
日期:——
Optically active oxirane-2-carboxylic esters, prepared from allylic alcohols employing the Sharpless epoxidation, were treated with sodium azide. The azido alcohols obtained were subsequently converted into aziridine-2-carboxylicesters by reaction with triphenylphosphine, in good yields and with high optical purity. Various racemic oxirane-2-carboxylic esters were subjected to the same sequence of
A simple route to syn α-Amino-β-Hydroxy esters by C-2 regioselective opening of a, β-Epoxy esters with metal halides
作者:Giuliana Righi、Giovanna Rumboldt、Carlo Bonini
DOI:10.1016/0040-4020(95)00873-7
日期:1995.11
α,β-Epoxyesters are opened by NaX (X = I, Br) in a regio and stereoselective fashion to β-hydroxy-α-halo esters, which represent suitable precursors of synα-amino-β-hydroxyesters and β-hydroxy esters.
Regiochemical control of the ring opening of 1,2-Epoxides by means of chelating processes. 11. Ring opening reactions of aliphatic mono- and difunctionalized cis and trans 2,3- and 3,4-Epoxy Esters
The regiochemical outcome of the ring opening of 1,2-epoxides through chelation processes assisted by metal ions, was verified in the azidolysis of simple aliphatic cis and trans 2,3- and 3,4-epoxy esters and in the corresponding derivatives bearing an ether functionality (OBn) in an allylic relationship to the oxirane ring. The results indicate that the behavior of these epoxides is influenced both by the opening conditions (standard or metal-assisted) and the promoting metal salt [LiClO4 or Mg(ClO4)(2)].