A highly diastereoselective synthesis of trans-2-substituted cyclopentylamines via a tandem hydrozirconation/Lewis acid-mediated cyclization sequence applied to butenyl oxazolidines is described. The method allows an easy preparation of diversely substituted cyclopentylamines which appear to be useful synthetic intermediates. This was further illustrated by the syntheses of (±)-Rodocaine, (±)-trans-pentacin
A new method for synthesis of rodocaine (1) is presented. Two key steps were carried out by the N-bromosuccinimide (NBS)-mediated intermolecular addition of known enamine 5 with allyltrimethyl silane in presence of boron trifluoride etherate (BF3/OEt2) and the intramolecular ring-closing metathesis of triene 3. The Diels-Alder cycloaddition of triene 3 with different ethyl propiolates was also studied. (C) 2011 Elsevier Ltd. All rights reserved.