N-Carbamothioylamino-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximide

The title compound, C9H9N3O3S, comprises a racemic mixture of chiral molecules containing four stereogenic centres. The cyclohexane ring tends towards a boat conformation, while the tetrahydrofuran ring and the dihydrofuran ring adopt envelope conformations. The dihedral angle between the thiosemicarbazide fragment and the fused-ring system is 77.20 (10)°. The crystal structure is stabilized by two intermolecular N—H⋯O hydrogen bonds.

The title compound, C 9 H 9 N 3 O 3 S, comprises a racemic mixture of chiral molecules containing four stereogenic centres. The cyclohexane ring tends towards a boat conformation, while the tetrahydrofuran ring and the dihydrofuran ring adopt envelope conformations. The dihedral angle between the thiosemicarbazide fragment and the fused-ring system is 77.20 (10) . The crystal structure is stabilized by two intermolecular N-HÁ Á ÁO hydrogen bonds.
Shandong Provincial Natural Science Foundation, China, is thanked for support (ZR2009BL027).
We report here the crystal structure of the title compound, (I) which comprises a racemic mixture of chiral molecules containing four stereogenic centres. The cyclohexane ring tends towards a boat conformation, the tetrahydrofuran ring and the dihydrofuran ring adopt envelope conformations (Fig. 1). The bond lengths and bond angles are normal range and comparable to those in the similar compound [Goh, et al., 2008] as representative example. The dihedral angle between the thiosemicarbazide fragment and fused-ring system is 77.20 (10)°. The crystal structure is stabilized by two intermolecular N-H···O and one intramolecular N-H···N hydrogen bonds (Table 1, Fig. 2).
The solution was filtered to remove impurities, and then the filtrate was left for crystallization at room temperature. The single-crystal suitable for X-ray determination was obtained by evaporation from the methanol solution after 5 d.

Refinement
H atoms were initially located from difference maps and then refined in a riding model with C-H = 0.93-0.96 Å and U iso (H) = 1.2U eq (C) or 1.5U eq (methyl C). Fig. 1. The molecular structure of (I), with the atom-numbering scheme. Displacement ellipsoide are drawn at 30% probability level.

Figures
supplementary materials sup-2  as those based on F, and R-factors based on ALL data will be even larger.