THE SYNTHESIS OF OCTOSYL NUCLEOSIDES BASED ON INTRAMOLECULAR OXYSELENATION OF A CONJUGATED DIENE

A new stereoselective ring construction for 3,7-anhydrooctofuranosyl n ucleoside, which is based on a 6-endo-trig oxyselenation of a conjugat e diene, (5'S)-C-(4-phenyl-1,3-butadienyl)uridine, was developed. Beca use of the appropriate array of Functionalities at the 5', 6', and 7'- positions, the cyclization product 14 can be considered to be a versat ile synthon for the synthesis of a series of octosyl nucleoside antibi otics. Factors governing the efficiency of this cyclization are also d iscussed. (C) 1998 Elsevier Science Ltd. All rights reserved.