A Versatile Total Synthesis of Trachycladines A and B and Their Analogues

The synthesis of marine nucleosides trachycladines A and B and two nucleoside analogues was accomplished following a versatile and high-yielding scheme starting from D-ribose. The key step involved a regio- and stereoselective direct Vorbruggen glycosylation reaction between the appropriate nucleobase and a common intermediate, 2-C-methyl-D-5-deoxyribofuranose triacetate.