(1R,3R,4R,7S)-7-allyl-7-benzyloxy-1-(4,4'-dimethoxytrityl)oxymethyl-3-(thymin-1-yl)-2,5-dioxabicyclo[2.2.1]heptane

(1R,3R,4R,7S)-7-benzyloxy-1-(4,4'-dimethoxytrityl)oxymethyl-7-(2-hydroxyethyl)-3-(thymin-1-yl)-2,5-dioxabicyclo[2.2.1]heptane