A Convenient Preparation of a Bicyclo[3.3.3]undecane Derivative Containing Heteroatoms Through a Rearrangement Step

A convenient method for the preparation of a bicyclo[3,3,3]undecane derivative via the Beckmann rearrangement of bicyclo[3,3,2]decane-9-one is described.     

The crystal structure of bicyclo [3.3.3]undecane-1,5-diol and the conformation of bicyclo[3.3.3]undecane (manxane)

The crystal structure of bicyclo [3.3.3]undecane-1,5-diol has been determined. It is monoclinic, P2₁/c, a = 12.99(2), b = 14.16(2), c = 12.50(1)A,β = 112.42(2)°, with two independent molecules in the asymmetric unit. One of these is disordered, but the other has almost exact C_3h symmetry and its conformation and precise molecular geometry agree well with previous calculations by molecular mechanics. The molecule shows considerable angle strain, having bridge angles in the range 118–121°     

Synthesis of a 1,2,7,8-Tetraoxa-spiro[5.5]undecane

Synthesis of a new spiro organic peroxide is described. The peroxy bonds were incorporated into the substrate framework via an acid-catalyzed ketal exchange reaction using hydrogen peroxide as the source of peroxy linkage. The hydroperoxyl groups were then bonded at the OH ends via Hg（II）-induced electrophilic additions to the C-C double bonds, giving a novel sprio structure with one peroxy bond in each of the two six-membered rings. The ester functionalities in the side chains also make it possible to conduct further structural modifications.     

Synthesis of novel 2,4,6,8,10-pentaaza[3.3.3]propellane derivatives

Propellanes and azapropellanes are attractive compounds for their unique structure and valuable applications but there are few synthetic studies for highly N-substituted azapropellanes. Several novel derivatives of 2,4,6,8,10-pentaaza[3.3.3]propellane, such as 3, 4, and 5 were successfully synthesized from readily available diethyl tartrate. Most of the synthetic steps were efficient. Their propellane structures were established by spectroscopic data and confirmed with single crystal X-ray analyses.     

Synthesis of 4,4′-bipentacyclo[5.4.0.02,6.03,10.05,9]undecane

A new bi-cage hydrocarbon, 4,4′-bipentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecane (12) was designed based on a strategy to construct two cages simultaneously from one key molecule scaffold. Thus 12 was conveniently synthesized from 5,5′-bi(cyclopentadiene) (9) through a three steps synthetic route in 23% overall yield. The new bi-cage hydrocarbon has high density (1.2322 g/cm³) and high volumetric heat of combustion (51.670 MJ/L).     

Eleuthesides and Their Analogs: XIII. Synthesis of Bicyclo[6.2.1]undecane System from Cyclohex-2-en-1-one

A short synthetic route to bicyclo[6.2.1]undec-9-ene-2,6-dione has been developed on the basis of retro-aldol reaction of 7-hydroxytricyclo[6.2.1.0^2,7]undec-9-en-3-one obtained from the Diels–Alder adducts of 3-tosylcyclohex-2-en-1-one with cyclopentadiene.     

2,8-二甲基-1,7-二氧杂螺[5,5]十一烷的合成

果蝇 ( Tephritidae)对水果生产有严重的危害 .热带果蝇寿命较长 ,具有很强的迁徙能力和繁殖能力 .因此开展果蝇生物防治和控制措施的相关研究具有重要的意义 [1,2 ] .Baker等 [3]发现性成熟的雌B.dorsalis果蝇 ,性腺分泌物中包含有螺环缩酮化合物 2 ,8-二甲基 - 1 ,7-二氧杂螺 [5 ,5 ]十一烷 ( 1 ) .Bactrocera Latifrons( Hendel)果蝇的雄性腺体分泌物中也存在螺环缩酮 1 [4 ] ,另外在 rove甲虫腹梢分泌物中也分离出 1 [5] ,螺环缩酮不仅作为性信息素组分存在于许多果蝇腺体中 ,而且作为结构单元存在于许多复杂的有强烈生理活性的天然…     

Bicyclo [3.3.0]Octane Derivatives for Carbaprostacyclin Synthesis

Convenient syntheses of the epimeric 3-hydroxy-2α-carb-oxybicyclo[3.3.0]octane-4α,6α-carbolactones are described which commence from the readily available cyclopentadienone dimer.     

Synthesis of Novel Triacetal Trioxa-Cage Compounds by Ozonolysis of Bicyclo[2.2.1]Heptenes and Bicyclo[2.2.2]Octenes

Several novel triacetal trioxa-cage compounds 11a-11g, 13, 15, 17 and 19 are synthesized in a short sequence. Ozonolysis of bicyclo[2.2.1]heptenes 4a-4c, 8a-8c, 10a, 10b and 14 in dichloromethane at ?78 °C followed by reduction with dimethyl sulfide gave triacetal oxa-cages 11a-11g, 13 and 15 in moderate yields, respectively. Ozonolysis of bicyclo[2.2.2]octenes 16 and 18 under the same reaction conditions gave triacetal oxa-cages 17 and 19 in moderate yields, respectively.     

Synthesis of versatile bicyclo[5.4.0]undecane systems from tetrachlorocyclopropene

2,2,3,4-Tetrachloro-8-oxabicyclo[3.2.1]octa-2,6-diene, derived in a single step from the cyclocondensation of furan and tetrachlorocylopropene, serves as a key intermediate for the construction of bicyclo[5.4.0]undecane synthons. Conversion to a meso-1,3 diketone is followed by a high yielding Robinson annulation reaction. Studies on the reduction of the enone product reveals a powerful preference for formation of the cis-ring fusion.     

Synthesis of heterocyclic [3.3.3]propellanes via a sequential four-component reaction

A highly chemoselective heteroannulation protocol for the synthesis of unreported polysubstituted heterocyclic [3.3.3]propellanes has been developed by sequential four-component reaction of ninhydrin, malononitrile, primary amines, and dialkyl acetylenedicarboxylates under mild conditions in water. To the best of our knowledge, there are no previous reports for the synthesis of these classes of heterocyclic [3.3.3]propellanes. The merit of this sequential Knoevenagel condensation/enamine formation/Michael addition/cyclization sequence is highlighted by its high atom-economy, excellent yields, the use of water as reaction media, and the efficiency of production without the use of any activator or metal promoters. This synthesis serves as a nice addition to group-assistant-purification (GAP) chemistry in which purification via chromatography and recrystallization can be avoided, and the pure products were obtained simply by washing the crude products with 95% ethanol.     

级联反应以及双环[2,2,2]辛烯酮的合成

研究了合成桥环化合物1的级联反应,不仅得到已知桥环化合物1,还得到了具有双环[2.2.2]辛烯酮的新桥环化合物2以及两个新的烯丙基取代的呫吨酮3和4。并对可能的反应机理进行了解释。     

2,8,9-trioxa-5-aza-1-silabicyclo[3.3.3]undecane—efficient reagent for the synthesis of 1-substituted silatranes

Russian Journal of Organic Chemistry - The reaction of silatrane HSi(OCH2CH2)3N with mercury(II) salts HgX2 (X = OCOMe, OCOCF3, OCOCCl3, SCN, Br) afforded the corresponding 1-substituted silatranes...     

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 Bicyclo[4.2.0]Octa-3,7-Diene-2,5-Diones

The bicyclo[4.2.0]octa-3,7-diene-2,5-diones (1) are of interest in that they are valence isomers of 1,4-cyclooctatetraenoquinones. The most obvious route for the formation of such compounds is the [2+2] photoaddition of alkynes to p-benzoquinones. Such a reaction has been observed in the case of 1,4-naphthoquinones. With p-benzoquinones, however, it has been observed in the case of 2-methoxy-p-benzoquinone (2a) alone, while p-benzoquinone (2b) and chloranil (2c) give products derived from addition of acetylenes to a carbonyl rather than an ethylenic bond; ^3,4 such products also accompany the products from 1,4-naphthoquinones referred to above.^1,3