An asymmetric synthesis of natural (-)-pyrrolam A starting from natural (S)
-malic acid is described. The stereogenic center was established via a high
ly trans-diastereoselective reductive alkylation procedure. A tandem base-i
nduced intramolecular amide N-substitution and tosic acid elimination led t
o the target molecule. (C) 1999 Elsevier Science Ltd. All rights reserved.