abstract
The synthesis of a new series of warfarin analogues by convenient organobase catalyzed 1,4-conjugate addition of 4-hydroxycoumarin to chalcone derivatives is described. H-1 NMR spectroscopy evidenced the presence of a predominant acyclic open-form together with the cyclic hemiketal tautomers of the resulting Michael adducts. The acyclic open-form has been unequivocally proved by single-crystal X-ray diffraction analysis. The use of the B ring ortho-hydroxychalcone synthons in this reaction has led to a diastereoselective synthesis of warfarin bicyclo[3.3.1]nonane ketal derivatives. (C) 2015 Elsevier B.V. All rights reserved.
keywords
DERIVATIVES; ANTICOAGULATION; CONFORMATIONS; THERAPY
subject category
Chemistry
authors
Talhi, O; Fernandes, JA; Pinto, DCGA; Paz, FAA; Silva, AMS
our authors
Filipe Alexandre Almeida Paz
Principal Researcher
José Alberto Pires Fernandes
Post-doc Fellowshipacknowledgements
Thanks are due to the University of Aveiro, Fundacao para a Ciencia e a Tecnologia (Portugal), EU, QREN, FEDER, COMPETE, for funding the Organic Chemistry Research Unit (project PEst-C/QUI/UI0062/2013), and the Portuguese National NMR Network (RNRMN). We would like to thank the General Directorate for Scientific Research and Technological Development-DGRSDT of Algeria for the financial support. We further wish to thank the Associated Laboratory CICECO (FCT grant PEst-C/CTM/LA0011/2013; FCOMP-01-0124-FEDER-037271) for funding the purchase of the single-crystal X-ray diffractometer, O. Talhi also thanks the project New Strategies Applied to Neuropathological Disorders (CENTRO-07-ST24-FEDER-002034), co-funded by QREN,