A facile access to peptides containing<scp>D</scp>-α-methyl β-alkylserines by coupling of α-branched leuchs anhydrides with α-amino esters
作者:Claudia Palomo、Jesus M. Aizpurua、Raquel Urchegui、Jesus M. Garcia
DOI:10.1039/c39950002327
日期:——
A new one step synthesis of α,α-disubstituted α-amino acid N-carboxy anhydrides from α-hydroxy β-lactams and their coupling with α-aminoesters promoted by KCN is described.
Construction of Quaternary Stereogenic Centers via [2 + 2] Cycloaddition Reactions. Synthesis of Homochiral 4,4-Disubstituted 2-Azetidinones and Imine Substituent Effects on β-Lactam Formation
作者:Claudio Palomo、Jesus M. Aizpurua、Jesus M. García、Regina Galarza、Marta Legido、Raquel Urchegui、Pascual Román、Antonio Luque、Juan Server-Carrió、Anthony Linden
DOI:10.1021/jo962017z
日期:1997.4.1
A study on the asymmetric construction of quaternary stereogenic centers via [2 + 2] cycloadditionreaction of ketenes with ketimines is described. Reaction of achiral ketenes and chiral alpha-alkoxy ketone-derived imines resulted in formation of new beta-lactams as single diastereomers. The cycloaddition was extended to pyruvate imines, aralkyl ketone-derived imines, and dialkyl ketimines. In these