Alkylation of Phenylglycinol-Derived Oxazolopiperidone Lactams. Enantioselective Synthesis of β-Substituted Piperidines
datasetposted on 2006-05-12, 00:00 authored by Mercedes Amat, Carmen Escolano, Oscar Lozano, Arantxa Gómez-Esqué, Rosa Griera, Elies Molins, Joan Bosch
The stereochemical outcome of the alkylation of a variety of phenylglycinol-derived oxazolopiperidone lactams is studied. The influence of the configuration of the C-8a stereocenter and the effect of the substituents at the C-8 and C-8a positions on the stereoselectivity of the reaction are discussed. The synthetic utility of these alkylation reactions is illustrated with the synthesis of cis and trans 3,5-disubstituted, 2,5-disubstituted, and 2,3,5-trisubstituted enantiopure piperidines, and the indole alkaloids 20R- and 20S-dihydrocleavamine.
alkylation reactionsPiperidinedihydrocleavaminestereocenterinfluenceciindole alkaloids 20 Rstereochemical outcomeAlkylationutilitysynthesispiperidinevarietySubstitutedLactam20 StrisubstitutedOxazolopiperidonesubstituentstereoselectivitylactamconfigurationoxazolopiperidonetrandisubstitutedenantiopureEnantioselective Synthesis