A stereoselectivesynthesis of (−)-allosedamine is disclosed. β-Aminosulfoxide 4 was generated stereoselectively by condensation of the sulfinyl anion 2 with N-Ts imine 3. The bromohydrin 5 was obtained by intramolecular sulfinyl group participation and the piperidine ring of allosedamine was elaborated using the ring-closing metathesis (RCM) reaction.
The Wacker-type oxidation is an important procedure catalyzed by palladium complexes. A mild and general method for the preparation of beta-substituted-beta-oxosulfoxides from the corresponding-substituted -gamma,delta-unsaturated sulfoxides is described. The products are versatile synthetic intermediates for the preparation of syn- and anti-1,3-diol and 1,3-aminoalcohol derivatives. (c) 2008 Elsevier Ltd. All rights reserved.