abstract
A facile and rapid access to bridgehead oxygen-and nitrogen-containing spiro bisheterocycles is reported. It involves a one-pot spiro-to-spiro ring transformation of the key spiro[chromanone-hydantoin] compounds into new substituted spiro [hydantoin-diazole], spiro [hydantoin-isoxazole], spiro [hydantoin-diazepine], spiro [hydantoinoxazepine], and spiro [hydantoin-benzodiazepine] upon reaction with appropriate bisnucleophilic agents. The hydantoin cycle is preserved during these chemical reactions affording the spiro bisheterocycles in optimal yields (42-71%). This relevant spiro-to-spiro ring transformation was confirmed by NMR and single-crystal X-ray diffraction studies.
subject category
Chemistry
authors
Talhi, O; Pinto, DCGA; Paz, FAA; Hamdi, M; Silva, AMS
our authors
Filipe Alexandre Almeida Paz
Principal Researcheracknowledgements
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. O. Talhi also thanks the project New Strategies Applied to Neuropathological Disorders (CENTRO-07-ST24-FEDER-002034), co-funded by QREN,