Two new chiral nucleoside analogues: (4R,5R)-4-(4,6-dimethylpyrimidin-2-ylsulfanyl)-5-[(2S,5R)-2-isopropyl-5-methylcyclohexyloxy]-2,3,4,5-tetrahydrofuran-2-one and (4R,5R)-5-[(2S,5R)-isopropyl-5-methylcyclohexyloxy]-4-(4-methyl-1,3-thiazol-2-ylamino)-2,3,4,5-tetrahydrofuran-2-one.

Synthesis and X-ray structural investigations have been carried out for the two title compounds, viz. C20H30N2O3S, (I), and C18H28N2O3S, (II). In both molecules, the cyclohexyloxy moiety and the conjugated cyclic system are located on opposite sides of the tetrahydrofuran-2-one ring. In the crystal structure of (II), there are two types of intermolecular hydrogen bonds, viz. C-H...S and N-H...O, and the molecules form a three-dimensional supramolecular architecture via the hydrogen bonds.