Diastereocontrolled synthesis of unit A of cryptophycin
摘要:
Cryptophycin fragment A was prepared in I I steps from protected methyl (R)-mandelate 4. A diastereoselective addition of magnesium acetylide to methyl mandelate and a Sharpless epoxidation followed by regioselective opening of the resulting epoxide allowed the synthesis of this intermediate in high diastereomeric purity. (C) 2001 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