First Synthesis of 2,3,4-Tri-O-benzyl-5-thio-d-ribono-1,5-lactone

Abstract

The first synthesis of 2,3,4-triO -benzyl-5-thio-D-ribono-1,5-lactone was achieved, in five steps, from 5-bromo-5deoxy-D-ribono-1,4-lactone; displacement of the bromide group, in methyl 2,3,4-triO -benzyl-5-bromo-5-deoxy-D-ribonate (7), gave methyl 2,3,4-triO -benzyl-5-S-acetyl-5-thio-D-ribonate (10) in 96% yield. Saponification of compound 10 gave the methyl 2,3,4-tri-Obenzyl-5-thio-D-ribonic acid (11) in 98% yield. Treatment of 11 with DIC-HOBt as coupling reagents led, after cyclisation, the target compound, 2,3,4-triO -benzyl-5-thio-D-ribono-1,5-lactone (12) in 75% yield.