Nucleosides and nucleotides part 187 -: Alternative synthesis of cyclic IDP-carbocyclic ribose.: Efficient cyclization of an 8-bromo-N1-[5-(phosphoryl)carbocyclic-ribosyl]inosine 5′-phenylthiophosphate derivative mediated by iodine

An efficient synthesis of cyclic IDP-carbocyclic-ribose, as a stable mimic for cyclic ADP-ribose, was achieved. N-1-Carbocyclic-ribosylinosine derivative 15, prepared from N-1-(2,4-dinitrophenyl)inosine derivative 10 and an optically active carbocyclic amine 11, was converted to 8-bromo-N-1-carbocyclic-ribosylinosine bis-phosphate derivative 20. Treatment of 20 with I-2 in the presence of molecular sieves in pyridine gave the desired cyclic product 8 quantitatively, which was deprotected and reductively debrominated to give the target cyclic IDP-carbocyclic ribose (3). (C) 1999 Elsevier Science Ltd. All rights reserved.