摘要:
A new divergent synthesis of (+)- and (-)-ferruginine 4, via the optically active 8-benzyl-3-oxo-8-azabicy-clo[3.2.1]octane-2-carboxylates 6 is described. The P-keto ester intermediates 6 were prepared by a novel PLE-catalyzed asymmetric dealkoxycarbonylation of the symmetric tropinone-type diesters 5. The key problem in the synthesis is controlling the regioselectivity of the reaction at the 2- and 4-positions in the tropane framework of the P-keto ester 6 for introduction of the acetyl group. (C) 2002 Elsevier Science Ltd. All rights reserved.