An Unusual Dephosphorylation Reaction

Abstract

In the course of our work to prepare l¹, Z²-seco-nucleotides, an unusual dephosphorylation reaction took place. When compound 1 was subjected to transfer hydrogenation conditions, the expected product was not obtained. Instead, a crystalline solid that proved not to have phosphorus was isolated in 78% yield. ¹H and ¹³C nmr analyses confirmed the hydrogenolysis of the benzyl groups as well as the loss of the phenyl esters. with elemental analytical data suggested that the structure of the compound could be either the 2′,5′-anhydro (2, Rdbnd]H) or 3′,5′-an- hydro derivative 3. precluded the use of spectroscopic analyses to prove the struc-ture. However, based on our experience with related compounds, structure 2 was favored, and we set out to prove it by another synthetic route.