Bicyclo[3.3.1]nonane-2,9-dione derivatives

Conclusions Bicyclo[3.3.1]nonane-2,9-dione derivatives, containing substituents in the 7 position, were synthesized by the condensation of the morpholine enamines of 4-substituted cyclohexanones with acryloyl chloride.Translated from Izvestiya Akadeinii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1408–1410, June, 1976.     

Synthetic studies towards garsubellin A: synthesis of model systems and potential mimics by regioselective lithiation of bicyclo[3.3.1]nonane-2,4,9-trione derivatives from catechinic acid

Bridgehead lithiations have successfully been carried out on substrates derived from catechinic acid, which possess the core bicyclo[3.3.1]nonane-1,3,5-trione structure present in garsubellin A. Using an external quench method, various electrophiles have been incorporated at the C-5 bridgehead position in a one-step process that appears to be sensitive to the substitution pattern on the bicyclic system. Regioselective lithiation at the C-3 sp(2) centre was achieved by changing the base used from LDA to LTMP. Following the introduction of a prenyl substituent by bridgehead substitution, annulation of a THF ring, analogous to that in garsubellin A, was possible via an epoxidation-ring opening sequence. Oxidative modification of the catechol substituent of the catechinic acid core was possible to give systems with muconic acid, ortho-quinone or furan 2-carboxylic acid side chains.     

Four New Lignans with a Bicyclo[3.3.1]nonadienemethanol Skeleton from Cunninghamia lanceolata

Four unique bicyclo[3.3.1]nonadienemethanol lignans, designated lanceolatanins A ( 1 ), B ( 2 ), C ( 3 ), and D ( 4 ), along with one previously known compound, isolariciresinol ( 5 ), were isolated from the MeOH extracts of the heartwood of Cunninghamia lanceolata. Their structures were elucidated by application of various spectroscopic methods, including 1D‐ and 2D‐NMR techniques, to their acetylated derivatives 1a, 2a, 3a , and 4a . Their possible biosynthetic formations are also discussed.     

Zur elektronenstruktur vicinaler triketone: Bicyclo[3.1.0]hexan-2.3.4-trione

Bicyclo[3.1.0]hexane-2.3.4-trione and its 1.5-dimethyl derivative have been synthesized and investigated by means of photoelectron spectroscopy.     

Synthesis of (+/-)-clusianone: high-yielding bridgehead and diketone substitutions by regioselective lithiation of enol ether derivatives of bicyclo[3.3.1]nonane-2,4,9-triones

[Structure: see text] A concise synthesis of the polyprenylated acylphloroglucinol natural product, clusianone, in racemic form, is described. An Effenburger cyclization generated a core bicyclo[3.3.1]nonane-trione structure, which was then elaborated by means of regioselective lithiation reactions.     

Synthesis and Chemical Transformations of 7-Hydroxybicyclo[3.3.1]nonane-3-carbohydrazide

Russian Journal of Organic Chemistry - The reaction of 4-oxahomoadamantan-5-one with hydrazine gave (3-exo,7-endo)-7-hydroxybicyclo[3.3.1]nonane-3-carbohydrazide. The latter was reacted with...     

Reaction of methyl 4,9-dioxobicyclo[3.3.1]nonane-2-carboxylate with hydrazine hydrate

Vilnius University, Vilnius 2734. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 416–417, March, 1995. Original article submitted January 20, 1995.     

Bicyclo[3.3.1]nonane and its derivatives—IV : Reactions of some carbonyl derivatives of bicyclo[3.3.1]nonane with diazomethane

The reaction of bicyclo[3.3.1]nonane-2,6-dione with diazomethane in situ does not lead to the homologous bicyclo[4.3.1]decane-2,7-dione, but mainly to tricyclo[4.4.0.0^2,9]decan-9-ol-5-one. The structure of the latter was confirmed by the proton NMR spectra measured with an addition of Eu(DPM)₃, A mixture of tricyclo[4,4.0.0^2,9]decan-9-ol-5-one and bicyclo[4.3.1]decane-2,7-dione results when solutions of diazomethane are used. The reaction of bicyclo[3.3.1]nonane-2,6-dione monoethyleneacetal with diazomethane in situ yields predominantly bicyclo[4.3.1]decane-2,7-dione. Under the same conditions bicyclo[3.3.1]nonan-2-one gives with diazomethane in situ only bicyclo[4.3.1]decan-2-one.     

Molecular structure of 3,7-dimethyl-9-thia-3,7-diazabicyclo[3.3.1]nonane-9,9-dioxide

By a single crystal X-ray diffraction study the molecular structure of 3,7-dimethyl-9-thia-3,7-diazabicyclo[3.3.1]nonane-9,9-dioxide having a chair-chair conformation with a diequatorial arrangement of methyl groups at nitrogen atoms is determined. Compound 1 C₈H₁₆N₂O₂S crystallizes in the space group Pnma with the following cell parameters: a = 11.0262(3) Å, b = 14.4490(3) Å, c = 6.1780(3) Å.