[5-(ADENIN-9-YL)-5-DEOXYPENTOFURANOSYL]PHOSPHONATES - A NOVEL TYPE OF NUCLEOTIDE ANALOGS RELATED TO HPMPA .1. DERIVATIVES WITH L-ARABINO, D-ARABINO, 2-DEOXY-L-ERYTHRO AND 2-DEOXY-L-THREO CONFIGURATION

15-(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 Michaelis-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 afford the title 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.