Enantioselective Synthesis of (+)-α-Conhydrine and (-)-Sedamine by L-Proline-Catalysed α-Aminooxylation
作者:Tanveer Mahamadali Shaikh、Arumugam Sudalai
DOI:10.1002/ejoc.201000169
日期:——
An efficient organocatalytic approach to the enantioslective synthesis of two important piperidine alkaloids, namely (+)-α-conhydrine (98 % ee) and (-)-sedamine (95 % ee), by L -proline-catalysed α-aminooxylation of aldehydes has been developed. The strategy involves an intramolecular cyclization to construct the piperidine core.
A new asymmetric route to 2-substitutedpiperidines involving the Sharpless asymmetric dihydroxylation (AD) of 5-hexenylazide 1 and an intramolecular aminocyclization as crucial steps and its application to the asymmetric synthesis of four piperidine alkaloids, (+)-coniine 2, (−)-pelletierine 3, (+)-δ-coniceine 4, and (+)-epidihydropinidine 5 is presented.