Download PDF
Synthesis 2000; 2000(2): 305-320
DOI: 10.1055/s-2000-6261
feature article
© 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.

The Stereoselective Synthesis of 2-Substituted 3-Azabicyclo[3.2.0]heptanes by Intramolecular [2+2]-Photocycloaddition Reactions

Thorsten Bach* , Christa Krüger, Klaus Harms
  • *Philipps-Universität Marburg, Fachbereich Chemie, D-35032 Marburg, Germany; Fax +49 (64 21) 2 82 89 17; E-mail: bach@chemie.uni-marburg.de
Further Information

Publication History

Publication Date:
31 December 2000 (online)

  PDF Download  Permissions and Reprints All articles of this category

The stereoselective synthesis of the 3-azabicyclo[3.2.0]heptanes 6, 12, 13, 17, 22, 23 and 24 by an intramolecular [2+2]-photocycloaddition is described. The product yield was good to excellent in almost all cases studied (65-87%) except for a single example (21 → 24) in which a low yield was recorded (22%). The facial diastereoselectivity of the reaction is high if α-branched N,N-diallylamines are employed as starting materials which either bear a comparably bulky α-substituent (25) or the α-substituent of which is connected to the nitrogen atom via an oxazolidinone ring (16, 19, 20, 21). These diallylamines were readily prepared from methionine and it was shown that their preparation proceeded free of racemization. The photocycloaddition could be conducted in two ways. The more general method is based on the Cu-catalyzed reaction which was carried out with Cu(OTf)2 in diethyl ether and is applicable to essentially all substrates under scrutiny. The N-cinnamyl substituted substrates 5, 11, 16 and 25 which possess a comparably low lying T1 state reacted well in a triplet-sensitized process employing acetophenone as the sensitizer and acetone as the solvent.

photochemistry - cycloadditions - stereoselective synthesis - bicyclic compounds - heterocycles

      >