181589-00-4Relevant academic research and scientific papers
The first asymmetric Carroll rearrangement diastereo- and enantioselective synthesis of polyfunctional ketones with vicinal quaternary and tertiary stereogenic centers
Enders, Dieter,Knopp, Monika,Runsink, Jan,Raabe, Gerhard
, p. 1095 - 1116 (2007/10/03)
The first asymmetric Carroll rearrangement opens up an efficient access to highly functionalised ketones 4 and 7 with vicinal quaternary and tertiary stereogenic centres of excellent diastereo- and enantiomeric purity (de = 89-96%, ee = 82 to >98 %) by using the SAMP/RAMP hydrazone methodology. Starting from hydrazones (S)-2, we describe a dianionic and a Lewis acid-mediated variant of the [3.3]-sigmatropic Carroll rearrangement. The relative and absolute configuration of the new stereogenic centres created by C-C bond formation were assigned by X-ray crystallographic analysis of the hydrazones 3h and 3j. VCH Verlagsgesellschaft mbH, 1996.
