cis- and trans-1-[3-(Hydroxymethyl)-1,4-dioxepan-5-yl]pyrimidines: a new nucleoside prototype with a seven-membered moiety

We synthesized nucleoside analogues with a seven-membered moiety as the carbohydrate fragment mimicking the upper part of biologically active natural and synthetic nucleosides, starting from 3-iodomethyl-5-methoxy-1,4-dioxepane. The reaction sequence involved the substitution of the iodine atom by the acetoxy group, condensation with the nucleobases and subsequent saponification. The cis/trans mixtures of the target compounds were separated by reversed-phase preparative HPLC. The relative configurations of each of the hydrogen atoms of the cis and trans newly synthesized compounds were determined by spin decoupling, 2D NOESY and COSY experiments. None of this series showed activity in antiviral tests in cell cultures.