Synthesis 2006(23): 4087-4091  
DOI: 10.1055/s-2006-950345
SPECIALTOPIC
© Georg Thieme Verlag Stuttgart · New York

An Enantio- and Diastereoselective Synthesis of Fluorinated β-Aminoalkyl­oxepine Derivatives through Mannich and Ring-Closing Metathesis Reactions

Santos Fustero*a,b, Elisabet Estebana, Juan F. Sanz-Cerveraa,b, Diego Jiméneza, Fatemeh Mojarrada
a Departamento de Química Orgánica, Universidad de Valencia, Burjassot 46100, Spain
b Centro de Investigación Príncipe Felipe, Valencia 46013, Spain
Fax: +34(96)3544939; e-Mail: santos.fustero@uv.es;
Further Information

Publication History

Received 28 July 2006
Publication Date:
02 November 2006 (online)

Abstract

The combination of a proline-catalyzed Mannich-type reaction between protected fluorinated aldimines and 4-pentenal followed by reduction and regioselective O-allylation gives γ-amino ethers that can then be used as substrates for ring-closing metathesis­ (RCM) reactions to afford fluorinated β-aminoalkyl­oxepines in a highly stereo- and enantioselective fashion.

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In the case of γ-amino alcohol 2c, however, the yield in the O-allylation reaction was substantially lower because of competitive side reactions. As the O-allylation product turned out to be very difficult to purify, we decided not to continue with this substrate.