Synthesis of peracylated derivatives of L-ribofuranose from D-ribose and their use for the preparation of β-L-ribonucleosides

A practical synthesis of peracylated derivatives of β-L-ribofuranose 13-15 from D-ribose was accomplished in 6 steps (total yield: 30-45% Compound 13 was employed for the preparation of 1-(β-L-ribofuranosyl)thymine (16) and -cytosine (17), which are key intermediates for the preparation of the nucleoside derivatives with β-L-configuration. Simultaneous transformation of 17 into β-L-ddC (19) and β-L-3'dC (20) was studied.