Regioselective synthesis of α,α-dialkylcyclopentanones from 1-hydroxycyclobutanecarboxylic acid or from O-protected cyclobutanone cyanohydrin
作者:Karine Estieu、Jean Ollivier、Jacques Salaün
DOI:10.1016/s0040-4020(98)00448-7
日期:1998.7
1-(1-Hydroxyalkyl)cylobutanols 4a-f, readily available either from 1-hydroxycyclobutane carboxylic acid or from O-protected cyclobutanone cyanohydrin, appeared the most suitable precursors for a regioselective synthesis of cyclopentanones α,α-disubstituted with various similar or different alkyl, alkenyl, aryl or cycloalkyl groups. The key steps consist of acid or Grignard reagent induced C4→C5 ring
An Efficient Procedure for the Preparation of 4-Substituted 5-Aminoimidazoles
作者:Mark McLaughlin、Rafat M. Mohareb、Henry Rapoport
DOI:10.1021/jo026257s
日期:2003.1.1
co-reactants. Thus, it is possible to easily prepare a diverse array of substituted heterocyclic compounds in good yield. The requisite alpha-aminonitriles were synthesized either from amino acids or by phase-transferalkylation of a glycine anion equivalent. The unstable free 5-aminoimidazoles were normally protected in situ to provide derivatives (methyl imidates or N,N-dimethylamidines) that were amenable