STEREOSELECTIVE SYNTHESIS OF 4-DEOXY-4-NUCLEOBASE-2,5-ANHYDRO-L-MANNITOL DERIVATIVES

2,5:3,4-Dianhydro-L-talofuranose dimethylacetal 7 was synthesized from D-glucose in 7 steps. A series of 4-deoxy-4-nucleobase-2,5-anhydro-L- mannitols 13-16 were synthesized regioselectively from 7 in good yield s. O-p-Tolylsulfonyl-2,5:3,4-dianhydro-L-talofuranose dimethylacetal 8 reacted with uracil or thymine to give the corresponding isonucleosid es 17 and 19, but in the case of reaction of 8 with adenine, reformati on of tetrahydrofuran ring took place, giving (S)-adenyl-5-(R)-[1'-(R) -hydroxy-2',2'-dimethoxyl] ethyl-2,3-dihydrofuran 21 and 4-deoxy-4-ade nyl-2,5:3,6-dianhydro-L-mannofuranose dimethylacetal 22. (C) 1997 Else vier Science Ltd.