Synthesis and characterisation of 3-aza-7-phosphabicyclo[3.3.1]nonan-9-ones

Novel 3-aza-7-phosphabicyclo[3.3.1]nonan-9-ones have been synthesised via the Mannich reaction of a phosphorinanone, a primary amine and formaldehyde. The new phosphorus-nitrogen (PN) compounds are rigid and adopt a twin-chair conformation both in solution and the solid states. The coordination properties of the PN compounds were explored and a stable platinum complex was synthesised in which the PN ligand was bonded through both donor atoms.     

Synthesis of N-arylmethyl-3-azabicyclo[3.3.1]nonan-9-ones

Russian Journal of Organic Chemistry -     

Crystal and molecular structure of 6,6-dimethyl-cis-2,4-diphenyl-3-aza-7-oxabicyclo[3.3.1]nonan-9-one

A method is presented for synthesizing 6,6-dimethyl-2,4-diphenyl-3-aza-7-oxabicyclo[3.3.1]nonan-9-one. The x-ray structure shows that the compound in the crystal exists in the chair-boat conformation with the piperidine ring in the boat form. The two phenyl substituents in the 2- and 4-positions are responsible for such a conformation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1400–1402, October, 1990.     

Reactions of 3-substituted 3-azabicyclo[3.3.1]nonan-9-ones with nitrogen-containing nucleophiles

Condensation of 3-substituted 3-azabicyclo[3.3.1]nonan-9-ones with hydroxylamine and hydrazine hydrate gave the corresponding oximes, hydrazones, and azines. Reductive amination of the title compounds in the presence of sodium triacetoxyhydridoborate led to the formation of 3-substituted 3-azabicyclo[3.3.1]nonan-9-amines which were converted into the corresponding dihydrochlorides by treatment with dry hydrogen chloride. Treatment of 3-tert-butoxycarbonyl derivatives with HCl under analogous conditions was accompanied by elimination of the tert-butoxycarbonyl group to produce 3-azabicyclo[3.3.1]nonan-9-amine dihydrochlorides.     

Synthesis and structure of 7-alkoxyalkyl-3-thia-7-zabicyclo[3.3.1]nonan-9-ones and several of their derivatives

New 7-alkoxyalkyl-3-thia-7-azabicyclo[3.3.1]nonan-9-ones were synthesized by the double Mannich cyclization of tetrahydrothiopyran-4-one with suitable alkoxyalkylamines and paraformaldehyde in acetous methanol. Wolff-Kishner decarbonylation of these bicyclic ketones gave 7-alkoxyalkyl-3-thia-7-azabicyclo[3.3.1]nonanes. The reduction of 7-alkoxyalkyl-3-thia-7-azabicyclo[3.3.1]nonan-9-ones by alkali metal hydride complexes leads to a mixture of two stereoisomeric secondary alcohols, which are epimers at C₍₉₎. Active analgesic, antiarrhythmic, and antibacterial compounds were found among these products. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 585–592, April, 2006.     

Synthesis and Properties of 3-Thia-9-azabicyclo[3.3.1]nonan-7-one

N-Benzyl-3-thia-9-aza-bicyclo[3.3.1]nonan-7-one has been prepared from methyl 4-bromocrotonate by reaction sequence involving sodium sulfide, benzylamine, and Dieckmann condensation. Some spectral and chemical properties of this system are also reported.     

Synthesis of chiral 3, 7-diazabicyclo[3.3.1]nonan-9-ones containing (R)-amino acid fragments

Russian Chemical Bulletin - A reaction of diethyl 1, 3-acetonedicarboxylate with formaldehyde and (R)-alanine, (R)-valine, (R)-leucine, and (R)-phenylalanine ester hydrochlorides gave nonracemic 1,...     

Synthesis and properties of 3-substituted 3-azabicyclo-[3.3.1]nonan-9-amines

Catalytic hydrogenation of 3-benzyl- and 3-tert-butoxycarbonyl-3-azabicyclo[3.3.1]nonan-9-one oximes over Raney nickel gave the corresponding 3-substituted 3-azabicyclo[3.3.1]nonan-9-amines which were converted into amides via reactions with acetyl and chloroacetyl chlorides and maleic and succinic anhydrides, into Schiff bases by condensation with benzaldehyde and 4-chlorobenzaldehyde, and into isothiocyanates by treatment with thiophosgene in the presence of K₂CO₃. 3-Benzyl- and 3-tert-butoxycarbonyl-3-azabicyclo-[3.3.1]nonan-9-yl isothiocyanates readily reacted with methanol, aniline, and sodium azide to produce methyl thiocarbamate, thiourea, and dihydrotetrazole-5-thione derivatives having a 3-azabicyclo[3.3.1]nonane fragment.     

Reaction of 3-methylenebicyclo[3.3.1]nonan-7-one with amines

Conclusions 3-Methylenebicyclo[3.3.1]nonan-7-one forms addition products with piperidine and N,N-dimethylaniline in the presence of their hydrochlorides, but with piperidine in the presence of its hydrochloride it forms 1,3-dipiperidinoadamantane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1161–1163, May, 1986.     

X-ray diffraction study of 2,4-diphenyl-9-ethynyl-3-azabicyclo-[3.3.1]nonan-9-ol

Kazakh State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2. pp. 179–181, March–April, 1993.     

Study of the Steric Structure of 7-Alkoxyalkyl-3-oxa-7-azabicyclo[3.3.1]nonan-9-ones and Their Derivatives Using 1H NMR Spectroscopy

Using the ¹H NMR spectroscopic method it has been shown that 7-alkoxyalkyl-3-oxa-7-azabicyclo[3.3.1]nonan-9-ones and 7-alkoxyalkyl-3-oxa-7-azabicyclo[3.3.1]nonanes exist in deuterochloroform solution in a double chair conformation. 7-(3-Butoxypropyl)-3-oxa-7-azabicyclo[3.3.1]nonan-9-ol is a 1:1 mixture of the two stereoisomeric alcohols. One of them exists in a double chair conformation having an equatorial hydroxyl group with relation to the piperidine ring and the other in a chair-boat conformation having an axial hydroxyl group which involves an intramolecular hydrogen bond with the unshared electron pair of the nitrogen atom.     

Conformational effect in 2,4-diphenyl-3-aza-6,6-dimethyl-7-oxabicyclo [3.3.1]nonan-9-ol C21H25O2N

Kazakh State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 5, pp. 167–169, September–October, 1991.     

Structure, Conformation, and Stereodynamics of N-Nitroso-2,4-diaryl-3-azabicyclo[3.3.1]nonanes and N-Nitroso-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones(1)

The variable temperature (1)H, (13)C, and (19)F NMR spectra were measured for the title N-nitrosamines. The observed unusually low N-N rotation barriers (12-15 kcal/mol) result from a significant deviation of the nitrosamino system from planarity. A pyramidal character of the amino nitrogen was confirmed by the X-ray crystal structures of two compounds and by bathochromic shifts of the n-pi absorption bands in the UV spectra. The nonplanarity of the nitrosamino moiety is due to the strong pseudoallylic A((1,3)) strain caused by the steric interaction of the NNO group with the neighboring aryl substituents fixed in the equatorial positions of the bicyclic skeleton. In addition, the barriers to the C-C rotation of aryl groups were examined at temperatures lower than required to "freeze" the N-N rotation and different DeltaG() values were observed for the aryls oriented syn and anti to the nitroso oxygen.     

Revised stereochemistry of 3-AZA-3-methyl-6-cycloalkylamino-bicyclo[3.3.1]nonan-9-OLS

The re-examination of stereochemistry of the title compounds is reported. The present results suggest a more reasonable configuration assignments than previously described.     

Dehydration of tertiary bicyclo[3.3.1]nonan-9-ol-2-ones. Rearrangement to cis-fused hexahydroinden-1-ones

Dehydrations of the anti-ketol 5 and its isomer 10 have been studied. In both cases the 1-hydrindenones 6 and 7 have been almost quantitatively obtained (1:1 ratio) through skeletal rearrangement of the kinetically favoured 9-methylene bicyclononane 9. This strongly supports the hypothesis of a stepwise rearrangement driven by the relative stabilities of the involved carbonium ions.