Synthesis 2003(7): 1083-1086
DOI: 10.1055/s-2003-39170
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Stereoselective Synthesis of 3,4,5,6-Tetrasubstituted (1R,2R)-Diaminocyclo­hexanes by Zirconium-Promoted Reductive Cyclisation

Stefano Grillia, Gianluca Martellib, Diego Savoia*b, Carla Zazzettab
a Dipartimento di Chimica Organica ‘A. Mangini’, Università di Bologna, viale Risorgimento 2, 40136 Bologna, Italy
b Dipartimento di Chimica ‘G. Ciamician’, Università di Bologna, via Selmi 2, 40126 Bologna, Italy
Fax: +39(051)2099456; e-Mail: savoia@ciam.unibo.it;
Further Information

Publication History

Received 20 February 2003
Publication Date:
09 May 2003 (online)

Abstract

The reactions of η2-(1-butene)zirconocene with (4R,5R)-di[(1S)-phenylethyl]amino-1,7-octadienes, carrying two vinyl or two phenyl substituents at C3 and C6, followed by protonation, gave a mixture of diastereomeric, fully substituted cyclohexanes. In the case of (4R,5R)-di[(1S)-phenylethyl]amino-(3R,6R)-diphenyl-1,7-octadiene, the main diastereomer of the product was isolated with 41% yield, then reductive removal of the N-substituents afforded (1R,2R)-diamino-(4R,5S)-dimethyl-(3R,6R)-diphenylcyclohexane with 91% yield.

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Supporting information available: ¹H NMR spectra assignments for 5a, b and 7a; COSY 45 and NOESY spectra of the aliphatic regions of 5a, b and COSY sprectra of the aliphatic region of 7a.