U. Voigtmann et S. Blechert, Enantioselective synthesis of alpha,alpha'-disubstituted piperidines via ruthenium-catalyzed ring rearrangemeat, SYNTHESIS-S, (6), 2000, pp. 893-898
A new method for the enantioselective synthesis of alpha,alpha'-disubstitut
ed piperidines is described. Easily available cyclopentenones 5a,b rearrang
e via Ru-catalyzed RCM-ROM to heterocycles. Compound 6a is converted to the
indolizidine 13.