21618-68-8Relevant articles and documents
Conversion of Some Pyrimidine 2'-Deoxyribonucleosides into the Corresponding 2',3'-Didehydro-2',3'-dideoxynucleosides
Joshi, Bhalchandra V.,Rao, T. Sudhakar,Reese, Colin B.
, p. 2537 - 2544 (2007/10/02)
Thymidine 4b was converted into 2,3'-anhydro-1-(2'-deoxy-β-D-threo-pentofuranosyl)thymine 7b in ca. 65percent isolated yield by being heated at 155 deg C with an excess of diphenyl sulfite and 1-methylimidazole in N,N-dimethylacetamide solution. 2'-Deoxyuridine 4a, 2'-deoxy-5-ethyluridine 4c and 2'-deoxy-5-fluorouridine 4d were similarly converted into 2,3'-anhydronucleosides which were isolated as their 5'-O-(tert-butyldimethylsilyl) derivatives 8a, 8c and 8d in 51, 50 and 59percent yield, respectively.When the oxetane derivatives 5a-d, prepared by the literature procedure from the parent 2'-deoxynucleosides 4a-d, were heated with an excess of sodium hydride in N,N-dimethylacetamide solution at 100 deg C, they were converted into the corresponding 2',3'-didehydro-2',3'-dideoxynucleosides 6a-d in 68, 76, 69 and 74percent isolated yield, respectively.The latter compounds were similarly prepared from the 2,3'-anhydronucleosides 7a-d in 71, 81, 69 and 74percent isolated yield, respectively. 2,3'-Anhydro-5'-O-(tert-butyldimethylsilyl)-2'-deoxy-5-(trifluoromethyl)- and -5-iodo-1-(β-D-threo-pentofuranosyl)uracil 8e and 8f, which were themselves prepared from the parent 2'-deoxynucleosides 4e and 4f, respectively, in ca. 60 and 50percent yield, were converted by a three-step procedure via the intermediate 2'-deoxy-3'-(phenylseleno) derivatives 10e and 10f into the corresponding 2',3'-didehydro-2',3'-dideoxynucleosides 6e and 6f in 52 and 49percent overall yield, respectively.Compound 8e was also converted into 2',3'-dideoxy-5-(trifluoromethyl)uridine 11b and 3'-azido-2',3'-dideoxy-5-(trifluoromethyl)uridine 11c in 49 and 66percent overall yield, respectively.
