The title spiro-oxindole compound, C(26)H(23)N(3)O(3), was prepared by the reaction of isatin, 3-methyl-1-phenyl-2-pyrazolin-5-one and 5,5-dimethyl-cyclo-hexane-1,3-dione in an ethanol solution. The fused cyclo-hexene ring adopts an envelope conformation. The dihedral angle between the aromatic and pyrazoline rings is 23.70 (8)°. An intra-molecular C-H⋯O inter-action occurs. The crystal structu...

In the title compound, C(27)H(20)ClNO(3), the two cyclo-pentane rings adopt envelope conformations. The pyrrolidine ring also adopts an envelope conformation (with the spiro C atom as the flap) and its least-squares plane (fitted to five atoms) makes dihedral angles of 66.50 (9), 77.36 (8) and 73.76 (8)° with the chloro-benzene ring and the two 2,3-dihydro-1H-indene ring systems, respectively. ...

THE TITLE COMPOUND [SYSTEMATIC NAME: (8S)-8-methyl-6,9-diaza-spiro-[4.5]decane-7,10-dione], C(9)H(14)N(2)O(2), consists of two connected rings, viz. a piperazine-2,5-dione (DKP) ring and a five-membered ring. The DKP ring adopts a slight boat conformation and the bonded methyl group is in an equatorial position. The five-membered ring is in an envelope conformation. In the crystal structure, in...

In the anion of the title compound, (C6H11N2)[B5O6(OH)4], both six-membered borate rings adopt a flattened boat conformation with the spiro-B atom and its opposite O atom deviating from the remainders of the rings by 0.261 (3)/0.101 (2) and 0.160 (3)/0.109 (2) Å, respectively. The imidazolium cation also deviates from planarity due to rotation of the ethyl group (as indicated by the C-N-C-C tor...

In the title spiro-diclofen derivative, C(22)H(17)Cl(3)O(4), the cyclo-hexane ring adopts a chair conformation [four C atoms are planar with a mean deviation of 0.018 Å and the two C atoms at the flap positions deviate by 0.613 (4) and -0.668 (5) Å from the plane]. The dihedral angles between the furan ring and the two benzene rings are 55.78 (3) and 49.92 (3)°. Weak inter-molecular C-H⋯Cl inte...

In the title compound, C28H27NO3, the cyclo-hexa-none and isoxazole rings have envelope conformations, with the methyl-ene and spiro C atoms as the flaps, respectively. The mean plane of the isoxazole ring is inclined slightly to the p-tolyl ring, making a dihedral angle of 14.20 (9)°, and is nearly perpendicular to the mean plane through the tetra-lone moiety and to the meth-oxy-phenyl ring [d...

In the isoquinoline ring system of the title mol-ecule, C(22)H(20)N(2)O(5), the N-heterocyclic ring is in a half-boat conformation. The dioxa-2-aza-spiro ring is essentially planar [maximum deviation = 0.026 (1) Å] and forms dihedral angles of 22.53 (5) and 64.46 (5)° with the benzene and phenyl rings, respectively. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen...

In the title compound, C(19)H(18)Cl(2)O(4), the two non-planar six-membered heterocycles passing through the spiro-C atom both adopt chair conformations, and the dihedral angle between the two benzene rings is 7.2 (1)°. In the crystal, the enanti-omers with R and S configurations are generated by the symmetry elements of the centrosymmetric space group, forming a racemic crystal. Inter-molecula...

In the title compound, C29H23ClN4O4, the quinazoline-indole system and the indolin-2-one system are each essentially planar, with maximum deviations from their mean planes of 0.150 (2) and 0.072 (2) Å, respectively. The central pyrrolidine ring adopts a twisted conformation on the C-C bond involving the spiro C atoms. Its mean plane forms dihedral angles of 83.37 (9) and 86.56 (8)°, respectivel...

In the title compound, C26H22N2O4, the central pyrrolidine ring adopts a twist conformation and the cyclo-pentane ring of the dihydro-acenapthylene group adopts an envelope conformation with the spiro C atom as the flap. The naphthalene ring system of the dihydro-acenaphthyl-ene group forms dihedral angles of 83.4 (9) and 61.3 (7)°, respectively, with the mean planes of the pyrrolidine and indo...