POLYNUCLEOTIDE ANALOGS .6. SYNTHESIS AND CHARACTERIZATION OF ALTERNATING COPOLYMERS OF MALEIC-ANHYDRIDE AND DIHYDROPYRAN CONTAINING GUANINEDERIVATIVES

2-Amino-6-chloropurine was reacted with 2-(tosyloxymethyl)-2,3-dihydro -2H-pyran to give 2-(2-amino-6-chloropurin-9-ylmethyl)-2,3 (3) and its N-7-isomer (4), which were treated with 5% aqueous trimethylamine to result in 2-(guanin-9-ylmethyl)-2,3-dihydro-2H-pyran (5) and its N-7-i somer (6), respectively. (N-2-Acetylguanin-9-ylmethyl)-3,4-dihydro-2H- pyran (7) and -(N-2-acetylguanin-7-ylmethyl)-3,4-dihydro-2Hpyran (8), obtained by acetylation of compounds 5 and 6, were copolymerized with maleic anhydride to give the alternating copolymers 9 and 10, and they were hydrolyzed to result in l)tetrahydropyran-5,6-diyl}{1,2-dicarbox yethlene}] (11) and )tetrahydropyran-5,6-diyl}{1,2-dicarboxyethylene}] (12), respectively. Polymer 11 showed hypochromicity whereas 12 exhib ited hyperchromicity in aqueous solutions. Polymers 11 and 12 in aqueo us solutions showed very strong excimer fluorescence with the maximum intensities at 432 and 446 nm, respectively, at room temperature. The two polymers showed polyelectrolyte effects, e.g., very high GPC molec ular weights as well as reduced viscosities at low concentrations in w ater. Normal behavior was retained by addition of inorganic salts. Sod ium salts of polymers 11 and 12 migrated to the anode by electrophores is and both showed two bands. (C) 1995 John Wiley & Sons, Inc.