Collect. Czech. Chem. Commun.
2010, 75, 1259-1272
https://doi.org/10.1135/cccc2010103
Published online 2010-11-24 08:42:02
Model synthesis of six-membered carbocyclic spironucleosides
Radim Nencka, Hubert Hřebabecký* and Martin Dračínský
Centre for New Antivirals and Antineoplastics, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Gilead Sciences & IOCB Research Centre, 166 10 Prague 6, Czech Republic
Abstract
Model study focusing on the synthesis of carbocyclic spironucleosides is presented. Hydantoin base was built on the easily accessible ketone precursors by Bucherer–Bergs reaction. On saturated substrates the reaction proceeded smoothly. On α,β-unsaturated ketones, however, the Bucherer–Bergs reaction competed with Michael addition of cyanide ion. We showed that the equilibrium of the reaction could be significantly shifted depending on the applied reaction conditions. Significant diastereoselectivity was observed for tandem Michael addition/Bucherer–Bergs reaction.
Keywords: Spironucleosides; Carbocyclic; Bucherer–Bergs reaction; Michaels addition; Tandem reaction; Diastereoselective synthesis; Ultrasound sonication.
References: 28 live references.
