Synthesis of Regio- and Stereoisomers of Highly Functionalized 1,2,3- Triazole-substituted Cyclopentanes

Highly functionalized regio- and stereoisomers of 1,2,3-triazole-substituted cyclopentanes were prepared in six steps from either bicyclic β-lactam 7 or γ-lactam 23 by 1,3-dipolar cycloaddition of the azido cyclopentanol intermediates with acetylenes. The reactions of azido aminocyclopentanols with non-symmetric acetylenes resulted regioselectively in the corresponding 1,4-disubstitued triazole derivatives under both thermal and Cu(I)-catalysed conditions. These compounds can be regarded as highly functionalized 1,2,3-triazole-modified carbocyclic nucleoside analogues.