Synthesis of two precursors of heterocarbocyclic nucleoside analogues. Discussion

The racemic heterobicyclic amino alcohols 6 and 7, which are of interest as intermediates in the synthesis of nucleoside analogues with heterobicyclic pseudosugars, were efficiently prepared from 2-thienylsuccinic acid via methyl 4-hydroxyimino-5,6-dihydro-4H-cyclopenta[b]thiophene-6-carboxylate [(′)-14). The target compounds were obtained together by direct reduction of (′)-14 with AlH 3 in refluxing THF, and were separated by flash chromatography of their N-acetylated derivatives.