(+)-(S,S)-1,3-Bis[(tetra-hydro-furan-2-yl)-meth-yl]thio-urea.

The title compound, C(11)H(20)N(2)O(2)S, is an enanti-omerically pure heterocycle-substituted thio-urea synthesized under solvent-free conditions. The thio-urea unit adopts a ZZ conformation, with the HN-(C=S)-NH core almost planar and the tetra-hydro-furfuryl groups placed below and above this plane. The whole mol-ecule thus approximates to noncrystallographic C(2) symmetry. Unexpectedly, the C=S group is not involved in inter-molecular hydrogen bonding, as generally observed in homodisubstituted thioureas. Instead, mol-ecules form a one-dimensional network based on weak N-H⋯O(heterocycle) hydrogen bonding, resulting in a zigzag ribbon-like structure around the crystallographic 2(1) screw axis along [100].