Synthesis of 4′-C-Ethynyl-β-D-arabino- and 4′-C-Ethynyl-2′-deoxy-β-D-ribo- pentofuranosyl Pyrimidines, and Their Biological Evaluation

4′-C-Ethynyl-β-D-arabino-pentofuranosyl thymine (14) and cytosine (16), and 4′-C-ethynyl-2′-deoxy-β-D-ribo-pentofuranosyl thymine (25) and cytosine (27) were synthesized by properly protected 4′-C-hydroxy-methyl-3,5-di-O-benzyl-α-D-ribo-pentofuranose (1) from D-glucose. Among them, 2′-deoxy derivatives 25 and 27 exhibited antiviral activity, while cytidine derivatives 16 and 27 inhibited the growth of neoplastic cells.