A practical route to enantiopure 3-hydroxy-pyrrolidines: application to a straightforward synthesis of (-)-bulgecinine

A practical synthesis of enantiopure substituted 3-hydroxy-pyrrolidines is reported. In four steps, starting from commercially available amino acids as chiral educts, this method allows for an efficient preparation of a variety of 3-hydroxy-pyrrolidines, as well as 3-hydroxy-piperidines and azepanes. Application of this methodology for a straightforward asymmetric synthesis of (-)-bulgecinine is also described. (C) 2007 Elsevier Ltd. All rights reserved.