The asymmetric unit of the title compound, C(28)H(21)NO(3)S, contains two mol-ecules with similar geometries. The thia-zolidine rings adopt half-chair conformations while the pyrrolidine and the diketo-substituted five-membered carbocyclic rings are in envelope conformations with the spiro C atoms at the flaps. In one mol-ecule, the phenyl ring forms dihedral angles of 57.76 (12) and 71.79 (12)...

In the mol-ecule of the title compound, C(16)H(13)N(3)O(4), the atoms of the spiro pyran ring are nearly planar with a maximum deviation of 0.095 (2) Å. The indole and pyran rings are oriented at a dihedral angle of 87.3 (9)°. In the crystal, mol-ecules are linked by inter-molecular N-H⋯N and N-H⋯O hydrogen bonds.

In the title compound, C(9)H(15)NO·C(6)H(2)Cl(2)O(4) [sytematic name: 2-aza-spiro-[4.5]decan-3-one-chloranilic acid (1/1)], the cyclo-hexane ring of the lactam molecule adopts a slightly distorted normal chair conformation and the five-membered 3-aza-spiro ring is in a slightly distorted chair conformation. The dihedral angle between the least-squares planes of the cyclohexane and 3-azaspiro ri...

The structures of natural products from a variety of sources contain spirocycles, two rings that share a common atom. The spiro motif is finding increasing inclusion in drug candidates, and as a structural component in several promising classes of chiral ligands used in asymmetric synthesis. Total syntheses of products containing all-carbon spirocycles feature several common methods of ring clo...

In the title compound, C(27)H(20)BrNO(3), the pyrrolidine ring adopts a half-chair conformation, while the other five-membered rings adopt flattened envelope conformations with the spiro C atoms as the flap atoms. An intra-molecular C-H⋯O hydrogen bond occurs, generating an S(6) ring. In the crystal, mol-ecules are connected via weak C-H⋯O hydrogen bonds, forming chains along the c axis.

In the title spiro-phosphazene derivative, C33H46N9OP3, the phosphazene and six-membered N/O rings are in flattened chair and twisted-boat conformations, respectively. The naphthalene ring system and the pyridine ring are oriented at a dihedral angle of 41.82 (4)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules related by translation along the a axis into chains. C-H⋯π inter-acti...

In the title mol-ecule, C(30)H(36)N(4)O(3), the dihedral angle between the planes of the xanthene and spiro-lactam rings systems is 88.69 (4)°. Both C atoms of one of the ethyl groups are disordered over two sites with occupancies 0.72 (2)/0.28 (2). The conformation of the mol-ecule may be influenced by two intra-molecular hydrogen bonds.

In the title compound, C(14)H(22)O(4) (systematic name: 9-hy-droxy-1,5,5-trimethyl-1,8-epidi-oxy-spiro-[5.5]decan-2-one), which was isolated from the fermentation broth of Steccherinum ochraceum, the two six-membered rings adopt chair conformations and are bridged by a peroxide group. The hy-droxy H atom forms a three-centre cyclic inter-molecular O-H⋯(O,O') hydrogen-bonding inter-action with a...

In the title compound, C(19)H(16)Cl(4)O(4), the two halves of the mol-ecule are related by a crystallographic twofold rotation axis passing through the central spiro-C atom. The two non-planar six-membered heterocycles both adopt chair conformations, and the dihedral angle between the two benzene rings is 76.6 (1)°. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecu...

In the title compound, C(17)H(15)N(3)O(4), the atoms of the spiro pyran ring are nearly planar with a maximum deviation of 0.0188 (14) Å. The benzene and pyrrole rings make a dihedral angle of 5.71 (6)°. The indole system and the pyran ring are oriented at a dihedral angle of 82.94 (3)°. The crystal structure is stabilized by inter-molecular classical and non-classical N-H⋯O, N-H⋯N and C-H⋯O hy...