Hydroboration of [(1R*,2R*,4R*)-7-oxabicyclo[2.2.1]hept-5-en-2-yl]methyl benzoate (5), which was prepared by Diels–Alder reaction of furan with acrolein and subsequent reduction and benzoylation of the Diels–Alder product, afforded [(1R*,2S*,4S*,6S*)-6-hydroxy-7-oxabicyclo[2.2.1]heptan-2-yl]methyl benzoate (6) and [(1R*,2R*,4R*,5S*)-5-hydroxy-7-oxabicyclo[2.2.1]heptan-2-yl]methyl benzoate (7). The key intermediates, [(1R*,2S*,4S*,6R*)-6-hydroxy-7-oxabicyclo[2.2.1]heptan-2-yl]methyl benzoate (10) and [(1R*,2R*,4R*,5R*)-5-hydroxy-7-oxabicyclo[2.2.1]heptan-2-yl]methyl benzoate (11), were prepared from 6 and 7, respectively, by oxidation with pyridinium dichromate and subsequent reduction of the thus obtained ketones. The Mitsunobu reaction of 10 and 11 with 6-chloropurine and subsequent reductive deprotection with diisobutylaluminium hydride afforded 6-chloropurine derivatives, which were converted to other purine analogues. Thymine analogues were prepared by Mitsunobu reaction of 10 and 11 with 3-benzoyl-5-methylpyrimidine-2,4(1H,3H)-dione and subsequent methanolysis. The target compounds were tested for the activity against Coxsackie virus.

Centre for New Antivirals and Antineoplastics Institute of Organic Chemistry and Biochemistry Academy of Sciences of the Czech Republic v v i 166 10 Prague 6 Czech Republic

Lit.: 9