Synthesis of 6-phenyl-3-azabicyclo[4.2.1]nonane

The synthesis of the title compound was achieved in five steps in 19% overall yield. The key step was an intramolecular Mannich reaction.     

Synthesis of new alkynyl containing 9-azabicyclo[4.2.1]nonatrienes from diynes and azepines

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Synthesis of anti-9-Bromo- and anti-9-Chlorobicyclo[4.2.1]nonatriene via Bicyclo[4.2.1]nonatriene→Bicyclo[4.2.1]nonatriene Rearrangement

The first syntheses of 9-bromo- and 9-chlorobicyclo[4.2.1]nona-2,4,6-trienes were each achieved in three stereoselective steps from the 9,9-bis(selenophenyl) derivative 9 in 79% overall yield for the bromide and 64% for the chloride. A deuterium-labeling experiment reveals the first rearrangement of a bicyclo[4.2.1]nonatriene which leaves the ring system intact.     

Synthesis of Bridged Bicyclic Molecules using Halocarbenes. Derivatives of bicyclo[4.2.1]nonane

The addition of dichlorocarbene (generated by the interaction of sodium methoxide and ethyl trichloroacetate) to bicyclo[3.2.1]oct-2-ene, its 3-chloro and exo-3,4-dichloro derivatives gives the exo 1 : 1 adducts in yields of 94, 89 and 48%. By suitable chemical reactions of these adducts, convenient syntheses of bicyclo[4.2.1]nona-2,4-diene and bicyclo[4.2.1]non-3-ene, together with their monochloro, dichloro and trichloro derivatives are obtained. Bicyclo[4.2.1]-nonan-3-one is also obtained from bicyclo[4.2.1]non-3-ene in a synthesis starting from the readily available 5-hydroxymethylnorborn-2-ene in an overall yield of 20%.     

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.     

3-Azabicyclo[3.3.1]nonane Derivatives: V. Synthesis of 7-Polyfluoroalkoxy-1,5-dinitro-3-azabicyclo[3.3.1]non-6-enes

A number of 7-polyfluoroalkoxy-1,5-dinitro-3-azabicyclo[3.3.1]non-6-enes were synthesized by reduction of 3,5-dinitrophenyl polyfluoroalkyl ethers with sodium tetrahydridoborate, followed by the Mannich reaction with formaldehyde and primary amines.     

Synthesis of highly functionalized 7-azabicyclo[2.2.1]heptadienes

Highly functionalized 7-azabicyclo[2.2.1]heptadiene derivatives have been synthesized via a [4 + 2] cycloaddition reaction between N-acyl-3,4-disubstituted pyrroles and ethynyl p-tolyl sulfone 5.     

Substituierte 9-Oxabicyclo[4.2.1]- und 9-Oxabicyclo[3.3.1]nonane III. neue ergiebige synthese von 2, 7-dioxatwistan und endo-2-hydroxy-9-oxabicyclo[3.3.1]nonen-(6)

Iodine cleavage of the [3.3.1]-iodomercuri compound 4 , easily prepared from cis, cis-cyclooctadiene-(1,5) by oxymercuration of the monoepoxide 1 (→ 3 ) followed by treatment with potassium iodide, leads to three isomeric iodides 6, 7 , and 8 , the [3.3.1]-exo-iodo isomer 8 being the predominant product. Intramolecular substitution in 8 opens an attractive new route to unsubstituted 2,7-dioxatwistane ( 19 ) [2], whereas dehydrohalogenation of 7 and 8 yields the unsaturated alcohol 17 [2], a suitable starting material for the preparation of substituted 2,7-dioxatwistanes [2], 2,7-dioxaisotwistanes ( e ) [2], and 2,8-dioxa-homotwistbrendanes ( f ).     

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

Russian Journal of Organic Chemistry -     

Synthesis of Si- and N-containing bicyclo[4.2.1]nona-2,4-dienes and bicyclo[4.2.1]nona-2,4,7-trienes

A [6π+2π] cycloaddition of Si- and N-containing alkynes and 1,2-dienes to cyclohepta-1,3,5-trienes in the presence of the two-component catalytic system (acac)₂TiCl₂-Et₂AlCl gives rise to the corresponding bicyclo[4.2.1]nona-2,4-diene and bicyclo[4.2.1]nona-2,4,7-triene derivatives.     

The synthesis of 7-hydroxy-3, 9-diazabicyclo[3.3.1]nonane

7-Hydroxy-3, 9-diazabicyclo[3.3.1]nonane is synthesized, starting from the dimethyl ester of the 4-hydroxypiperidine-2, 6-dicarboxylic acid, by preparing the N-benzyl derivative and cyclizing the latter with benzylamine to the benzylimide of the 1-benzyl-4-hydroxypiperidine-2, 6-dicarboxylic acid. On reduction of the given imide with lithium aluminum hydride and catalytic hydrogenolysis of the benzyl groups, the final 7-hydroxy-3,9-diazabicyclo[3.3.1]nonane is obtained, the three-dimensional structure of which (chair-chair type) is proved by comparison of its methyl derivative with a known compound of demonstrated three-dimensional structure.