Nucleosides. IX. Synthesis of Purine N³,5′‐Cyclonucleosides and N³,5′‐Cyclo‐2′,3′‐seconucleosides via Mitsunobu Reaction as TIBO‐like Derivatives

Abstract

The Mitsunobu reaction was applied to prepare, in one step, purine N ³,5′‐cyclonucleosides 10a–d. A subsequent ring opening in the ribose moiety of the resultant N ³,5′‐nucleosides by sodium periodate led to the corresponding N ³,5′‐cyclo‐2′,3′‐seconucleosides. These products consist of 5‐, 6‐, and 7‐membered tricyclic system which is the basic skeleton of TIBO derivatives, known antiviral agents.

^#Previous paper in this series: Ref. 1.

^†In honor and celebration of the 70th birthday of Professor Leroy B. Townsend.

Keywords:

• TIBO
• Mitsunobu reaction
• N ³,5′‐cyclonucleoside
• N ³,5′‐cyclo‐2′,3′‐seconucleoside
• Formycin B

Acknowledgment

This work was supported by a research grant (No. NSC92‐2320‐B‐002‐080) from National Science Council of the Republic of China in Taiwan.

Notes

^#Previous paper in this series: Ref. 1.

^†In honor and celebration of the 70th birthday of Professor Leroy B. Townsend.