“…The 1-O-acetyl-2,3,5-tri-O-toluoyl-b-d-[1,2,3,4,5-13 C 5 ]-ribofuranose for the synthesis of labelled nucleosides was synthesized according to our earlier procedure. 34 Methylene chloride, ethyl acetate, cyclohexane, hexane, acetone, methanol and ethanol were distilled prior to use. Triethylamine and N,N-diisopropylethylamine (DIPEA) were distilled from CaH 2 and stored over molecular sieves (4 ( A A).…”