(3aR,4bS,4R,4aS,5aS)-4-(5,5-dimetil-1,3-dioksolan-2-il)heksahidrociklopropa[3,4]ciklopenta[1,2-b]furan-2(3H)-on
2′-deoxi-5′-O-(4,4′-dimetoxitrityl)-N2-isobutyrylguanosin-3′-(2-cyaoetyl-diisopropylfosforamidit)