Synthesis of 5'-deoxypseudouridine derivatives and related reactions

Abstract

A C-nucleoside derivative, 5-(5-deoxy-$\beta$-D-erythro-pent-4-enofuransyl)-1,3-dimethyluracil(33), which might be an important intermediate for transformations of pyrimidine ring and/or modifications of sugar moiety, was synthesized from pseudouridine via seven steps in 62\% overall yield. Pseudouridine was sequentially 1,3-dimethylated, 2``,3``-O-isopropylidenated, 5``-deoxy-5``-iodinated, deisopropylidenated, 2``,3``-di-O-acylated, dehydroiodinated, and finally deacylated to yield the desired compound. A derivative, 5-(3(R),4(R)-2,3- dihydroxy-4,5-epoxy-2,3-O-isopropylidene-1-penten-1-yl)-1,3- dimethyluracil(36) was obtained by treatment of 1,3-dimethyl-5-(2,3-O-isopropylidene-5-O-methanesulfonyl- $\beta$-D ribofuranosyl) uracil(34) with potassium tert-butoxide in dimethyl sulfoxide. 5-(5-Deoxy- 2,3-di-O-acetyl-$\beta$-D-erythro-pent-4-enofuranosyl)-1,3-dimethyluracil (32) was examined in the possibility of using it as an intermediate for the synthesis of other compounds by elimination or addition reactions.