Download PDF
Synlett 2000; 2000(7): 0983-0986
DOI: 10.1055/s-2000-6654
letter
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

A Stereodivergent Synthesis of Enantiopure 3-Methoxypyrrolidines and 3-Methoxy-2,5-dihydropyrroles from 3,6-Dihydro-2H-1,2-oxazines

Robert Pulz* , Toshiko Watanabe, Wolfgang Schade, Hans-Ulrich Reissig
  • *Institut für Chemie - Organische Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany; Fax + 49(0)30/8 38-5 53 67; E-mail: hans.reissig@chemie.fu-berlin.de
Further Information

Publication History

Publication Date:
31 December 2000 (online)

  PDF Download  Permissions and Reprints All articles of this category

Hydrogenolysis of syn-3,4-dihydro-2H-1,2-oxazine (syn-2) in the presence of palladium on charcoal provided a diastereomeric mixture of amino alcohols 3a/3b from which pyrrolidine derivative 4a was obtained as major isomer after cyclization. Reduction with Raney-nickel furnished 3b and finally 4b as major components. The same stereodivergent behavior was found with the corresponding anti-1,2-oxazine (anti-2) giving either 3c and 4c or 3d and 4d as major isomers. These results are explained by a probably inverted order of reaction steps during the reductions. Less reactive Raney-nickel allowed isolation of intermediates 5a and 5b, which could be converted into 2,5-dihydropyrrole derivatives 6a and 6b respectively.

1,2-oxazine - hydrogenation - pyrrolidine - pyrrole

      >