branched-chain nucleosides containing beta-d-apio-l-furanose were synthesized by condensation of the bis ( trimethylsiyl ) derivative of uracil ( 11 ) , thymine ( 12 ) , 5-fromouracil ( 13 ) , and 5-iodouracil ( 14 ) with the protected 1-o-acetylapiose in the presence of a friedel-crafts catalyst .
C0041917
uracil
C0040087
thymine