[5-(Adenin-9-yl)-5-deoxypentofuranosyl]phosphonates, a new type of nucleotide analogs with fixed HPMPA structure, have been prepared. The synthesis of compounds of L-arabino (IIa, IIb), D-arabino(XIVa, XIVb), 2-deoxy-L-erythro(IIIa, IIIb) and 2-deoxy-L-threo(IVa, IVb) configuration is based on the Michelis-Arbuzov reaction of the fully protected methyl glycosides with triethyl phosphite and trimethylsilyl triflate which leads to anomeric mixture of diethyl (L-pentofuranosyl) phosphonates. The protected 5-O-tosyl derivatives react with sodium salt of adenine to give N9-substituted products which after total deprotection afforded the tittle nucleotide analogs. The fixation of the partial structure of HPMPA to form five-membered ring leads to a significant decrease, or a total loss, of biological activity.
Noble Gas in a Ring