Simple access to novel azetidine-containing conformationally restricted amino acids by chemoselective reduction of β-lactams
作者:Guillermo Gerona-Navarro、Ma Angeles Bonache、Miriam Alı́as、Ma Jesús Pérez de Vega、Ma Teresa Garcı́a-López、Pilar López、Carlos Cativiela、Rosario González-Muñiz
DOI:10.1016/j.tetlet.2004.01.023
日期:2004.3
Reduction with diphenylsilane and catalytic amounts of tris(triphenylphosphine)rhodium(I) carbonyl hydride resulted in an efficient, chemoselective method for the transformation of amino-acid-derived beta-lactams into the corresponding azetidines, which after removal of the p-methoxybenzyl group, afforded a new family of conformationally restricted amino acids. Phe-derived compounds were obtained in enantiopure form by combining HPLC resolution of the beta-lactam precursor and the above-mentioned procedure. (C) 2004 Elsevier Ltd. All rights reserved.
Entry to New Conformationally Constrained Amino Acids. First Synthesis of 3-Unsubstituted 4-Alkyl-4-carboxy-2-azetidinone Derivatives via an Intramolecular <i>N</i><sup>α</sup><i>-C</i><sup>α</sup>-Cyclization Strategy
作者:Guillermo Gerona-Navarro、Maria Angeles Bonache、Rosario Herranz、Maria Teresa García-López、Rosario González-Muñiz
DOI:10.1021/jo015559b
日期:2001.5.1
N-benzyl-N-chloroacetyl aminoacidderivatives is described. This study resulted in the first concise and versatile route to the preparation of 3-unsubstituted 4-alkyl-4-carboxy-2-azetidinones, to be included into the scarce family of beta-lactams with quaternary centers at the C(4) position. Particularly noteworthy is that the intramolecular N(alpha)-C(alpha)-cyclization of Phe and Leu derivatives afforded the