7-Deazaadenosine, N-benzoyl-5′-O-[(2-cyanoethoxy)mercaptophosphinyl]-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-N,7-(1,3-propanediyl)-P-thio-7-deazaadenylyl-(3′→5′)-N-benzoyl-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-7-[3-[[[2-(trimethylsilyl)ethoxy]carbonyl]amino]propyl]-, cyclic nucleotide