Access to the synthesis of wybutosine, the first tricyclic fluorescent nucleoside isolated from phenyllalanine transfer ribonucleic acids

An improved synthesis of the key intermediate 5 for the chiral syntheses of wybutine (1c) and hydroxywybutine (1d) has been achieved by palladium-catalyzed vinylation, which has been utilized for the first synthesis of 3-β-D-ribofuranosylwybutine (2c).