Synthesis of 9-(.BETA.-D-arabinofuranosyl)adenine 5'-phosphate starting from adenosine 5'-phosphate.

Abstract

9-(.beta.-D-Arabinofuranosyl)adenine 5''-phosphate was obtained from adenosine 5''-phosphate via the novel intermediate 8,2''-O-cycloadenosine 5''-phosphate. In contrast to the synthesis of 9-(.beta.-D-arabinofuranosyl)adenine, it was difficult to cleave this compound by hydrogen sulfide directly to 8,2''-O-cycloadenosine 5''-phosphate because of a considerable degree of dephosphorylation. N-acylated 8,2''-O-cycloadenosine 5''-phosphate was readily cleaved at the cyclo-bond by hydrogen sulfide. Desulfurization of 8-mercapto-9-(.beta.-D-arabinofuranosyl)adenine 5''-phosphate gave the desired pure crystalline product.