Starting from commercially available lactone 10, a concise and highly diastereoselective synthesis of (-)-(1S,2R,8aS)-2-epi-lentiginosine (2) is described. The synthesis featured an unexpected highly erythro-selective reaction of Grignard reagent 7 with the protected N,O-acetal 8. The stereochemical outcome of this reaction is contrary to the known results involving the reactions with O-benzyl protected amino-furanosides and aminoglycosides. Thus, this method constitutes an extension of the threo-diastereoselective C-C bond formation methodology. (C) 2011 Elsevier Ltd. All rights reserved. ; NSF of China [20672089, 20832005]; NFFTBS [J1030415]; National Basic Research Program (973 Program) of China [2010CB833200]