High-yield syntheses of the bromide (1a) and picrate salts (1b) of the 5-azonia-spiro[4]nonane cation [(CH2)4N(CH2)4] are reported. In the single crystal X-ray diffraction analyses of the two salts the spirocyclic quaternary ammonium cations have their five-membered rings in envelop and twist conformations modified by packing forces. The conformation found experimentally for 1a has C2-symmetry ...

In the title compound, C(27)H(20)BrNO(3), two intra-molecular C-H⋯O hydrogen bonds both form S(6) rings. The pyrrolidine ring adopts a twisted conformation about the C-C bond bearing the indane ring systems. The other two five-membered rings within the indane systems are in shallow envelope conformations, with the spiro C atoms as the flap atoms. The mean plane of the pyrrolidine ring [maximum ...

The title compound, C(15)H(14)O(5), is a natural product, isolated from Sorbus lanata Syn. Pyrus lanata (D. Don) found in Pakistan. The compound is composed of three spiro-fused rings. The dihedral angle between the mean planes of the benzene rings is 4.81 (13)°. The meth-oxy groups are oriented at dihedral angles of 74.44 (14), 83.0 (2) and 66.3 (2)° with respect to the planes of the benzene r...

In the title compound, C(29)H(20)F(3)NO(3)S, the thia-zolidine ringadopts a half-chair conformation. The pyrrolidine and two five-membered carbocyclic rings are in envelope conformations with the spiro C atoms at the flaps. The trifluoro-methyl-substituted benzene ring forms dihedral angles of 62.37 (14) and 87.40 (14)° with the benzene rings of the dihydro-1H-indene units. The two benzene ring...

The racemic title compound, C30H26Cl3N3O2, comprises two spiro links, the first connecting the piperidine and pyrrolidine rings and the other connecting the indole and pyrrolidine rings. The piperidine ring adopts a half-chair conformation, while the pyrrolidine ring has an envelope conformation with the unsubstituted C atom as the flap. The dihedral angles between the two p-Cl-substituted benz...

The asymmetric unit in the title compound, C(33)H(34)N(2)O(2)·H(2)O, consists of a V-shaped mol-ecule and a water mol-ecule to which it is hydrogen bonded. The angle between the mean planes of the two spiro-connected indane groups is 77.06 (5)°. The two five-membered rings of the indane groups have envelope conformations with the methyl-ene atoms adjacent to the spiro C atom forming the flaps. ...

In the title compound, C23H23NO8, the dihedral angle between the five- and six-membered rings of the indene-dione moiety is 3.09 (13)°. The mean plane of the five-membered ring (which has a flat envelope conformation with the spiro C atom as the flap) is inclined to the mean plane of the central five-membered ring of the pyrrolizine unit by 76.48 (12)°. This central ring has a twist conformatio...

Radical-radical cross coupling reactions of photoexcited 9-fluorenones have been accomplished for the first time, leading to the synthesis of 9-alkyl, pyrollidinyl and spiro-THF derivatives of 9-fluorenones. The method also reveals, for the first time, the behaviour of ketyl radicals in decarboxyaltive alkylation and ring expansion reactions.

The [4.3.0]heterobicyclic title structure, C(19)H(14)BNO(3), is composed of a five-membered OBNC(2) ring and a six-membered OBNC(3) ring, each of which has an approximate envelope conformation. The coordination geometry of the B atom is distorted tetra-hedral. In the crystal structure, centrosymmetrically related mol-ecules are associated through pairs of O-H⋯O hydrogen bonds.

Five new spiro[indoline-3,3′-indolizine]s have been synthesized with high regio- and stereospecificity in one-pot three-component reactions between a substituted indole-2,3-dione, ( S )-pipecolic acid trans -3-benzoylacrylic acid, subsequently characterized using combination of elemental analysis, IR 1 H 13 C NMR spectroscopy, mass spectrometry crystal structure analysis. (1′ SR ,2′ ,3 RS ,8a′ ...