NEW NEPLANOCIN ANALOGS .10. THE CONVERSION OF ADENOSINE TO NEPLANOCIN-A, A CARBOCYCLIC NUCLEOSIDE ANTIBIOTIC WITH POTENT ANTIVIRAL ACTIVITY

Synthesis of neplanocin A, a potent antiviral carbocyclic nucleoside, from adenosine was achieved. An acyclic adeninenucleoside 21, prepared from adenosine, was converted to 4'-keto acyclic derivative 27. When 27 was treated with lithiotrimethylsilyldiazomethane in THF, a C-H ins ertion reaction at the 1'-position proceeded to give 6'-O-TBS-2',3'-O- isopropyrideneneplanocin A (29) along with its 1'-epimer 30. (C) 1997 Elsevier Science Ltd.