Nucleosides and nucleotides. Part 201: Alternative method to synthesize 9-(6,7-dideoxy-β-d-allo-hept-5-ynofuranosyl)adenine, a selective and potent ligand for P3 purinoceptor-like protein: a stereoselective reduction based on sugar puckering of the furano

An alternative stereoselective synthesis of 9-(6,7-dideoxy-β-d-allo-hept-5-ynofuranosy)adenine is described, which makes use of stereoselective reduction of methyl 5-C-trimethylsilylethynyl-5-oxo-2,3-di-O-tert-butyldimethylsilyl-β-d-ribofuranoside (4), followed by glycosidation with N6-benzoyladenine. It was revealed that sugar puckering of the furanose ring and steric hindrance of the protecting group were important factors for the stereoselective reduction.