Asymmetric Homologation of Ketones. A New Entry to Orthogonally Protected (2<i>R</i>,4<i>R</i>)-Piperidine-2,4-dicarboxylic Acid
作者:Pablo Etayo、Ramón Badorrey、María D. Díaz-de-Villegas、José A. Gálvez
DOI:10.1021/jo801515k
日期:2008.11.7
A new conformationally constrained analogue of glutamic acid has been synthesized efficiently in seven steps from a chiral 2-alkyl-4-piperidone. The synthesis is based on (a) the unprecedented asymmetric one-carbon homologation of the ketone controlled by the size of the N-substituent and (b) the appropriate manipulation of substituents at positions 2 and 4 of the piperidine ring, a step that involves