An enantioselective total synthesis of NK-1 receptor antagonists, (+)-CP-99,994 and (+)-CP-122,721, is described. The key steps are diastereoselective addition of vinyllithium to a chiral benzaldehyde oxime ether and diastereoselective borane reduction of a cyclic oxime ether. (C) 2002 Elsevier Science Ltd. All rights reserved.
Enantioselective Synthesis of Primary 1-(Aryl)alkylamines by Nucleophilic 1,2-Addition of Organolithium Reagents to Hydroxyoxime Ethers and Application to Asymmetric Synthesis of G-Protein-Coupled Receptor Ligands
previously used as an efficient chiral auxiliary for the synthesis of natural products in this laboratory. The synthetic utility of this methodology involving diastereoselective methyl addition was demonstrated by further application to the asymmetric synthesis of a new type of calcium receptor agonist (calcimimetics), (R)-(+)-NPS R-568 and its thio analogue. Furthermore, diastereoselective vinylation was accomplished