(4R,6S)-4-(2-(benzyloxy)ethyl)-6-ethynyl-2,2-dimethyl-1,3-dioxane

N6,N6-dibenzylformamidine-5'-O-[diethyl(ethoxycarbonyl)phosphonomethyl]-2',3'-O-isopropylidene adenosine

5'-O-[diethyl(ethoxycarbonyl)phosphonomethyl]-2',3'-O-isopropylidene adenosine

[1-tert-Butoxycarbonylmethyl-4-oxo-azetidin-(2Z)-ylidene]-(diethoxy-phosphoryl)-acetic acid ethyl ester

[1-tert-Butoxycarbonylmethyl-4-oxo-azetidin-(2E)-ylidene]-(diethoxy-phosphoryl)-acetic acid ethyl ester