944128-08-9Relevant articles and documents
Asymmetric synthesis of 6-alkyl- And 6-arylpiperidin-2-ones. Enantioselective synthesis of (S)-(+)-coniine
Lebrun, Stephane,Couture, Axel,Deniau, Eric,Grandclaudon, Pierre
, p. 2473 - 2476 (2008/02/05)
A variety of diolefinic hydrazides (1) have been assembled in a highly diastereoselective manner by addition of allyllithium to chiral SAMP hydrazones followed by N-acylation with acryloyl chloride. Substrates 1 undergo ring-closing metathesis to give the cyclic enehydrazides (5) which can be easily converted into virtually enantlopure 6-alkyl- or 6-arylpiperidin-2-ones (7). The versatility of this hydrazone addition-RCM protocol has been further exemplified by the conversion of the unsaturated heterocycle 5b into the piperidine alkaloid (S)-(+)-coniine.