Brian A. Otter

A novel stereospecific radical cyclization of 2',3'-O-isopropylideneuridine and -adenosine 5'-aldehyde to the corresponding 6,5'-cyclodihydrouridine and 8,5'-cycloadenosine derivatives

Abstract Treatment of 2′,3′- O -isopropylideneuridine 5′-aldehyde with tributyltin hydride in the presence of azobisisobutyronitrile affords (6 S ,5′ S )-6,5′-cyclo-5,6-dihydro-2′,3′- O -isopropylideneuridine in a stereospecific manner. A similar reaction with N 6 -benzoyl-2′,3′- O -isopropylideneadenosine 5′-aldehyde leads to the corresponding 8,5′-cycloadenosine.

C-Glycosylation of substituted heterocycles under Friedel-Crafts conditions. I: A two-step synthesis of the thieno[3,4-d]pyrimidine C-nucleoside analog of inosine

Abstract Direct stannic chloride catalyzed C-glycosylation of N-formyl-4-amino-3-carboalkoxy thiophenes with 1- O -acetyl-tri- O -benzoyl-β- D -ribofuranose, followed by annelation of a fused pyrimidone ring upon treatment with ammonia, constitutes a short approach to the synthesis of a new C-nucleoside inosine analog.

Synthesis of furo[3,2-d]pyrimidine nucleosides: A novel c-nucleoside isostere of adenosine

Abstract The synthesis of 4-amino-7-(β- D-ribofuranosyl)-furo[3,2- d ]pyrimidine, a new C-nucleoside analogof adenosine, is described. It involves base-catalyzed cyclization of the 2-(ribofuranosyl)-2-cyano ethers 3 to afford the ribosyl-3-amino-2-cyanofurans 4a and 4β, followed by a two step conversion into the desired furo[3,2- d ]pyrimidine system.

Studies on the Chemistry of 5-Acetoxy-6-(Acetoxymethyl)-Uridines: Synthesis of a New type of 5′-Cyclonucleoside1

Abstract The 5-acetoxy-6-(acetoxymethy1)-uridine derivative 18 is converted in aqueous sodium hydroxide solution into the imidazole cyclonucleoside 22. Compound 22, in which an oxygen bridge links the sugar and base methano groups, represents a new type of 5′-cyclonucleoside.