Studies on the Syntheses of the Hypermodified Nucleosides of Phenylalanine Transfer Ribonucleic Acids

Abstract

This review highlights the first total synthesis of (αS, βS)-β-hydroxywybutosine, the identity of which was established with fluorescent nucleoside isolated from rat liver tRNA^Phe. Three general prerequisites for the synthesis of the target are emphasized: construction of new 9-β-D-ribofuranosyl-3-methylpurines; the first syntheses of optically active γ-aryl-α,β-unsaturated amino acids; and a new method for hydrogenolysis of glycols through their cyclic carbonates to give the γ-aryl-β-hydroxy amino acid derivatives. The mechanism for the formation of cyclic carbonates from reactions of glycols with (COCl)₂ and highly selective preparation of the cyclic oxalates are also described.