Download PDF
Synlett 1990; 1990(2): 103-105
DOI: 10.1055/s-1990-21001
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.

Asymmetric Synthesis of C2-Symmetric Annulated Bicyclooctylcyclopentadienes

Zhuoliang Chen* , Ronald L. Halterman
  • *Department of Chemistry, Boston University, Boston, MA 02215, USA
Further Information

Publication History

Publication Date:
08 March 2002 (online)

  PDF Download  Permissions and Reprints All articles of this category

The efficient asymmetric preparation of the C2-symmetric annulated cyclopentadienes, (+)-(1R,7R,8R,10R)-8, 10-diisopropyltricyclo[5.2.2.02,6]undeca-2,5-diene (1) and (-)-(1S,7S,8R,10R)-8,10-dimethyltricyclo [5.2.2.02,6]undeca-2,5-diene(2) is described. The key step in these syntheses is an asymmetric dihydroboration of 1,4-dialkyl-1,4-cyclohexadienes using enantiomerically pure isopinocamphenylborane. The overall yield of enantiomerically enriched 1 or 2 is 27% and 20%, respectively, for the five-step synthesis (Birch reduction of 1,4-dialkylbenzene, asymmetric dihydroboration-oxidation, bis(methanesulfonate) formation, bisalkylation of cyclopentadiene, and [1,5]-sigmatropic rearrangement). The formation of chiral titanocene dichlorides is described.