2',3'-Cyclodialdehyde-5'-cytidylic acid AIDS-156475 AIDS156475 CMP-ribodialdehyde Formic acid compound with (3,5-dihydroxy-6-(4-imino-2-oxo-3,4-dihydro-1(2H)-pyrimidinyl)-1,4-dioxan-2-yl)methyl dihydrogen phosphate (1:1) NSC622992