Efficient Synthesis of Methyl 3,5-Di-O-benzyl-alpha-D-ribofuranoside and Application to the Synthesis of 2'-C-beta-Alkoxymethyluridines

摘要

Methyl 3,5-di-O-arylmethyi-alpha-D-ribofuranosides have been used extensively as synthons to construct 2'-C-branched ribonucleosides. Herein, we describe efficient access to methyl 3,5-di-O-arylmethyl-alpha-D-ribofuranosides (aryl: 2-CIC_6H_4, 3-CIC_6H_4, 4-CIC_6H_4, 4-BrC_6H_4, 2,4-CI_2C_6H_3, Ph) in 72-82% yields from methyl D-ribofuranoside. We also demonstrate efficient access to the versatile precursor methyl 3,5-di-O-benzyl-alpha-D-ribofuranoside (3f) and the synthesis of 2'-C-beta-methoxymethyl- and 2'-C-beta-ethoxymethyluridine in six steps from 3f with overall yields of 18% and 32%, respectively.