Heterotricyclodecane. XXVI. 2,6-Dioxatricyclo [3.3.2.03,7]decan,ein neuartiges isomers von 2,6-dioxaadamantan

2,6-Dioxatricyclo [3.3.2.0^3,7]decane, a Novel Isomer of 2,6-Dioxaadamantane Restriction among the great number of possible diheterotricyclodecanes to such with a carbocyclic 8membered ring (cyclooctane) as basic skeleton, which is crosswise bridged by two heteroatoms, and restriction to 5-, 6- and 7membered heterocyclic rings results in the isomeric diheterotricyclodecanes of the following five different structural types: 2,6-diheteroadamantane (a) , 2,7-diheteroisotwistane (b) , 2,7-diheterotwistance (c) , 2,8-diheterohomotwistbrendane (d) , and 2,6-diheterotricyclo [3.3.2.0^3,7]decane (e ; s. Scheme 1). Starting from a suitably C (5)^o(2)-functionalized 2,7-dioxaisotwistane, first representatives with the hitherto unknown skeleton of type e were prepared by molecular rearrangement involving neighboring group participation: 2,6-dioxatricyclo [3.3.2.0^3,7]decane (41) and the derivatives 34–40 thereof (Scheme 7).     

Heterotricyclodecane XXVII. Ein weiterer Zugang zu 2,6-Dioxatricyclo [3.3.2.03,7]decan

A Further Approach to 2,6-Dioxatricyclo[3.3.2.0^3,7]decane A further synthesis of 2,6-dioxatricyclo[3.3.2.0^3,7]decane ( 10 ) is described by bridging the 9-oxabicyclo[4.2.1]non-7-en-3endo-ol ( 9 ). The latter compound was prepared by ring expansion starting from the known 8-oxabicyclo[3.2.1]oct-6-en-3-on ( 1 ).     

A concise route to the C2-symmetric tricyclic skeleton of ryanodine

Ryanodine is a potent calcium channel modulator. In this Letter, we report the 10-step synthesis of the highly substituted tricyclic ring system of ryanodine. Diels-Alder reaction via dearomatization of 2,5-dimethylbenzene-1,4-diol and subsequent SmI₂-mediated reductive coupling of eight-membered 1,5-diketone efficiently introduced the four consecutive fully substituted carbons of the tricyclo[3.3.2.0^2,6]decane system.     

Reaction of 5-oxo-2-phenyl-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-benzodioxaphosphepine with chloral. The synthesis and spatial structure of 5-carbaphosphatrane containing a four-membered ring

Phosphorylation of 2-hydroxyphenyl 2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl ketone with dichloro(phenyl)phosphine gave 5-oxo-2-phenyl-4,4-bis(trifluoromethyl)-4,5-di-hydro-1,3,2-benzodioxaphosphepine. Heating of the latter initiated an intramolecular interaction of the P atom with the carbonyl group. Hydrolysis of the intermediate product yielded 3-hydroxy-2-oxo-2-phenyl-3-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]-2,3-di-hydro-1,2λ⁵-benzo[d]oxaphosphole. The reaction was highly stereoselective (P_RC_S/P_SC_R). The reaction of the starting phosphepine with chloral proceeded highly stereoselectively (P_RC_SC_S/P_SC_RC_R) to give a 5-carbaphosphatrane derivative containing a four-membered ring, namely, 1-phenyl-3-trichloromethyl-10,10-bis(trifluoromethyl)-6,7-benzo-2,4,8,9-tetraoxa-1λ⁵-phosphatricyclo[3.3.2.0¹,⁵]decene. The trigonal bipyramid of the 5-carbaphosphatrane derivative is made up of the equatorial O atoms and the apical C atoms.     

Tricyclo [3.3.2.03,7]decan (9-Homo-nor-adamantan) Synthese und Umwandlungen

Tricyclo[3.3.2.0^3,7]decane (9-Homo-nor-adamantane). Synthesis and Transformations A synthesis of tricyclo [3.3.2.0^3,7]decane (=9-homo-nor-adamantane; 1 ), which belongs to the adamantaneland, a family of nineteen isomeric C₁₀H₁₆ hydrocarbons, is described, as well as derivatives thereof. Treatment of protoadamantan-5endo-ol (11) with either thionyl chloride or phosphorus pentachloride yielded under rearrangement the chloride 18 , and solvolysis of the 5endo-chloro-protoadamantane (16) led to the acetate 26, 18 and 26 having both the tricyclo [3.3.2.0^3,7]decane skeleton. Subsequent transformations gave the title compound 1 as well as the corresponding olefin 8 .     

The structure of tricyclo[3.3.2.0]decane (hexahydrobullvalene) – A gas-phase electron diffraction (GED) study

The molecular structure of tricyclo[3.3.2.0^2.8]decane (hexahydrobullvalene) has been determined experimentally by gas-phase electron diffraction as well as by quantum chemical calculations. The bond lengths (twofold standard deviations in parentheses) in the skeleton [1.496(7) in the cyclopropane ring, 1.527(10) adjacent to it, 1.550(22) for the central bonds in the bridges and 1.548(16) Å for the bonds originating from the singular bridgehead] all can be explained in terms of the features of this cage hydrocarbon. All three CCC valence angles [113.0(8)° at the singular bridgehead, 112.8(12) adjacent to it and 122.3(20) adjacent to the skeletal cyclopropane ring] are larger than the regular tetrahedral angle on an sp³-hybridized carbon atom. The two-carbon bridges between the skeletal cyclopropane ring and the opposite bridgehead are twisted with a dihedral angle of 43(2)°, i.e. significantly less than the approximately 60° in n-butane in its synclinal (gauche) conformation.     

The Interaction of Walsh-Orbitols in Diademane and Related Hydrocarbons

To obtain further information concerning the interaction between Walsh-orbitols of ‘conjugated’ cyclopropane rings, the photoelectron spectra of the following compounds have been recorded: bicyclo[4.1.0]heptane 1 , cis- and trans-tricyclo[5.1.0^{3, 5}]octane 2, 3 , diademane 4 , trans-pentacyclo[3.3.2.0^{2, 9}.0^{4, 10}, 0^{6, 8}]decan 5 and bicyclo[4.1.0]heptene-2 6 . The first bands in the PE.-spectra of these compounds have been assigned on the basis of a ZDO HMO-approximation. For 2 and 4 the value for resonance integral between linked 2p atomic orbitals of two adjacent eclipsed cyclopropane rings is found to be ?1.73 eV.     

13C-NMR-spektren von spiro[2.4]hepta-(1,4,6)-trienen und -(4.6)-dienen

The ¹³C NMR spectra of [1.2]-spirenes 2 and spiro[2.4]hepta-(4.6)-dienes 5 are described and the effects of substituents are discussed. A bonding model of the [1.2]-spirenes 2 is derived on the basis of C-H coupling constants and calculated charge densities. The ¹³C NMR shifts of 1-aryl-spiro[2.4]hepta-(4.6)-dienes 6 show a good correlation with the Hammett σp constants of the substituents in p-position of the phenyl ring. Conclusions on spiroconjugation in [1.2]-spirenes 2 are drawn from comparing the ¹³C shifts of similar substituted [1.2]-spirenes and spiro[2.4]hepta-(4.6)-dienes. The spiroconjugation in [1.2]-, [2.2]- and [2.3]-spirenes 2, 3 and 4 is discussed comparing the calculated charge densities with the δ (¹³C) values, as well as the UV and p.e. spectra.     

Triple ring contraction of a [2+2] macrocyclic ligand

Schiff base condensation of 2,6‐diformylpyridine and 1,3‐diaminopropan‐2‐ol in the presence of a Ba^II template ion yields a complex containing a [2+2] macrocycle, [Ba₂(μ_1,2‐ClO₄)₂(H₂L1)₂], where H₂L1 is 3,7,15,19,25,26‐hexaazatricyclo[19.3.1.1^9,13]hexacosa‐1(25),2,7,9(26),10,12,14,19,21,23‐decaene‐5,17‐diol. On transmetallation with Cu^II cations, the macrocycle undergoes three successive ring contractions, yielding crystals of (acetato‐κO)[26,28‐dioxa‐3,7,15,19,25,27‐hexaazahexacyclo[19.3.1.1^2,5.1^9,13.1^17,10.0^3,8]octacosa‐1(25),9(27),10,12,14,21,23‐heptaene‐κ⁵N]copper(II) perchlorate, [Cu(CH₃COO)(C₂₀H₂₂N₆O₂)]ClO₄ or [Cu(CH₃COO)(L2)]ClO₄, in which the macrocycle ring size has been reduced from 20 members in H₂L1 to 16 in L2.     

Attempted Synthesis of Tricyclo[3.3.2.024]DEC-2(4)-ENE

The synthesis of tricyclo[3.3.2.0^2,4]-dec-2(4)-ene (3) has been attempted using a route analogous to those previously developed for 1 and 2. Complications were encountered in the synthesis. The conformational problems of the larger polycyclic structures in the synthesis of 3 must be more difficult to overcome than the increased angle strain of the smaller rings when 1 or 2 are synthesized.     

Höhere,kondensierte Ringsysteme. 5. Mitteilung[1]. Makrocyclen mit überbrückten 9, 10-Dihydrophenanthreneinheiten

Starting from 2, 7-diacetyl-9, 10-dihydrophenanthrene, 2, 7-dichloromethyl-9, 10-dihydrophenanthrene was synthesized through a serie of a new compounds. By a modified Wurtz reaction the dichloromethyl compound led to hexahydro-[2³] (2,7) phenanthrenophane and decahydro-[2⁵] (2,7) phenanthrenophane. [2³] (2,7) phenanthrenophane was obtained by dehydrogena tion of hexahydro-[2³] (2,7) phenanthrenophane with Pd/C. The structure of these new ring systems was confirmed by UV.-, NMR.- and mass spectroscopy.     

Nucleophilic and Electrophilic Properties of Carbenes,II. 4-Biphenylyl-4-pyridylcarbene

Flash pyrolysis of 4-biphenylyl-4-pyridyldiazomethane ( 4 gave 7-phenyl-2-azafluorene) 5 , which was also synthesized from 3-mesitoylpyridine in four steps. 4-Biphenylyl-4-pyridyl-[¹³C]-diazomethane ( 9 ) was prepared from isonicotinic [¹³C]-acid chloride in three steps. Flash pyrolysis of 9 established that 4a- and 4b-[¹³C]-7-phenyl-2-azafluorenes are formed in a carbene-carbene rearrangement in which ring expansion of the biphenyl part dominates over that of the pyridine ring. These results support the postulate that carbene-carbene rearrangements are favoured by a nucleophilic interaction between the filled singlet carbene sp² (σ) orbital and the lowest unoccupied molecular orbital (LUMO) of the aromatic ring.     

Preparation,spectral characterization,and single crystal X-ray structures of cis and trans isomers of 2,4,6-trifluoroethoxy-1,3,5-triethyl-1,3,5,2λ5, 4λ5, 6λ5-triazatriphosphorinane-2,4,6-trioxide, [ETNP(O)(OCH2CF3)]3

Oxidation of the cis isomer of the λ³-cyclotriphosphazane [EtNP(OCH₂CF₃)]₃ with trimethylamine-N-oxide (TMNO) gives the cis isomer of trioxo-λ⁵-cyclotriphosphazane [EtNP(O)(OCH₂CF₃)]₃; the trans isomer of [EtNP(O)(OCH₂CF₃)]₃ is obtained by the treatment of a cis and trans mixture of [EtNP(OCH₂CF₃)]₃ with aqueous H₂O₂. The two trioxocyclotriphosphazanes have been characterized by elemental analysis, IR, and NMR (¹H, ¹³C, ¹⁹F, and ³¹P) spectroscopy. The solid state structures of both the isomers have been determined by single crystal X-ray diffraction. The six-membered P₃N₃ ring in both the isomers exhibits a twist-boat conformation; in the cis isomer, the trifluoroethoxy substituents lie on the same side of the ring, whereas, in the trans isomer, two trifluoroethoxy groups are on one side of the ring and the third on the other side of the ring. Crystal data for cis-[EtNP(O)(OCH₂CF₃)]₃: monoclinic, P 2₁/ n , a = 13.593(3), b = 9.721(2), c = 17.539(3) Å, β = 99.49(2)°, V = 2286(1) ų, Z = 4, and Final R = 0.047. Crystal data for trans-[EtNP(O)(OCH₂CF₃)]₃: monoclinic, P 2₁/ n , a = 11.685(4), b = 15.115(5), c = 13.233(5) Å, - = 102.21(3)°, V = 2284(1) ų, Z = 4, and Final R = 0.078.     

Three Distinct Silver(I) Coordination Polymers: Bridging‐­Ligand Directed Syntheses,Crystal Structures,Luminescence, and Nitrobenzene Sensing Properties

Three distinct Ag^I‐DMAP [DMAP = 4‐(dimethylamino)pyridine] coordination polymers [Ag₂I₂(DMAP)₂]_n ( 1 ), [Ag₂(CN)₂(DMAP)_2.5 · DMAP]_n ( 2 ), and [Ag(SCN)(DMAP)]_n ( 3 ) were constructed by monatomic I^–, diatomic CN^–, and triatomic SCN^– bridges, respectively. 1 – 3 were determined by FT‐IR spectroscopy, elemental analyses, TGA, powder and single‐crystal X‐ray diffraction. 1 exhibits a 1D wavelike chain structure, sustained by 3‐connected I^– bridges, whereas 2 shows a unique 1D single‐ and double‐strand alternating chain, supported by 3‐connected CN^– bridges. Compound 3 has a 2D 3‐connected network architecture, fabricated by 3‐connected SCN^– bridges, and exhibits a (4 · 8²) topology. The luminescence and nitrobenzene sensing properties of 1 – 3 were explored in 2‐propanol suspensions, which revealed that compounds 1 – 3 exhibit DMAP originated luminescence emissions and are highly sensitive for nitrobenzene detection.     

Saturated heterocycles. 254 . synthesis and stereochemistry of saturated or partially saturated pyridazino-[6,1-b]- and phthalazino[1,2-b]quinazolinones

By the reaction of anthranilic hydrazide 1 with cis-2-(p-methylbenzoyl)-1-cyclohexanecarboxylic acid 2a or diendo-3-(p-methylbenzoyl)bicyclo[2.2.1]heptane-2-carboxylic acid 2b , fused tetra- and pentacyclic ring systems 3a, b were prepared, trans-2-Amino-1-cyclohexanecar-bohydrazide 4b was reacted with 3-(p-chlorobenzoyl)propionic acid 5 to yield the pyridazino[6,1-b]quinazolinone 6 . From the reaction of cis-2-amino-1-cyclohexanecarbohydrazide 4a with 2a , three isomeric partially saturated 8H-phthalazino[1,2-b]quinazolin-8-ones 7a-c were formed. The reaction of diexo-2-aminobicyclo[2.2.1]heptane-3-carbohydrazide 4c and 2a furnished the pentacyclic derivatives 8 and 9 containing a 3-aryl-4,5-dihydropyridazine or 3-arylhexahydropyridazine ring C with cis annelated C/D rings. The formation of 8 and 9 involving different ring systems can be rationalized by two reaction pathways: (i) in the bislactam 9 the carboxyl group acylates the hydrazide, while (ii) in 8 it forms a pyridazine ring with the cyclic amino group by cyclocondensation. The structures of the products were elucidated by ¹H and ¹³C nmr methods, including DEPT, DNOE and 2D-HSC measurements.     

Cyclization and rearrangements of diterpenoids. IX. Isomerization of (1R,2S,7S,10S,11R,12S,13S)-2,6,6,10,12-pentamethylpentacyclo[10.2.1.01,10.02,7.011,13]pentadecane by fluorosulfonic acid

It has been shown that the opening of the cyclopropane ring in (1R, 2S, 7S, 10S, 11R, 12S, 13S)-2,6,6,10,12-pentamethylpentacyclo[10.2.1.0^1,10.0^2,7.0^11,13]pentadecane takes place under the action of fluorosulfonic acid at all three carbon-carbon bonds, but at low temperatures the main isomerization product is (1R, 2S, 7S, 10S, 12S, 13S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadecan-13-ol, and at the ordinary temperature the main products are (1R, 2S, 7S, 11S, 12R, 13R)-2,6,6,11,13-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadeca-9-ene and (1S, 2R, 11S, 12R, 15R)-2,7,7,11,15-pentamethyltetracyclo[10.2.1.0^2,11.0^3,8]pentadeca-3(8)-ene.     

13C-NMR-spektren von bicyclo[n.1.0]alkenen

The ¹³C-NMR spectra of some bicyclo[3.1.0]hex-3-en-2-ols and of some bicyclo[3.1.0]hex-3-en-2-ones are described. The bond parameters of bicyclo[3.1.0]hex-3-en-2-one are derived from a structure determination of endo-6-methoxy-1,3,6-triphenylbicyclo[3.1.0]hex-3-en-2-one. The electron density is calculated by the EHT method, and correlated with the ¹³C NMR shifts. For comparison the ¹³C NMR spectrum of a bicyclo[4.1.0]hepta-1,5-dione derivative is analysed. The influence of a cyclopropane system attached to a five-membered and to a six-membered ring is elucidated. Whereas the five-membered ring shows conjugation between the carbonyl group and the cyclopropane system, the same effect is not observed in the six-membered ring analogue. This is explained by the highly rigid structure of the five-membered ring.     

The Quest for Bridgehead Bridgehead Dications with Bicyclo[2.2.2]octyl Skeletons

It is predicted by MINDO/3 calculations that the 1,5-trishomobarrelenediyl dication 4 would be as much stabilized over the bicyclo[2.2.2]octanediyl dication 3 as the monocation 7 -H is energetically favored over the hypothetical 1-bicyclo[2.2.2]octyl 10 -H. In spite of this, the bridgehead cations generated from the 1,5-dihalo-trishomobarrelenes 6 -F, 6 -Cl, 6 -Br, and 6 -I and from the 1,5-diol 6 -OH under long-lived ion conditions were only the 5-substituted monocations 7 -F, 7 -Cl, 7 -Br, 7 -I, and 7 -OH, respectively, unequivocally identified by their ¹H- and ¹³C-NMR spectra as well as quenching products. Although there is efficient charge delocalization in 7 -X, as revealed by the ¹³C-chemical shifts, the lack of formation of the bridgehead bridgehead dication 4 is not due to an unforeseen destabilization by the three α-annellated cyclopropyl groups. Even the 1,5-dichlorotetracyclo[3.3.2.0^2,4.0^6,8]decanes 17 -Cl₂ and 19 -Cl₂ and 1,5-dichlorotricyclo[3.2.2.0^2,4]nonane 12 -Cl₂ with only two and one α-cyclopropyl groups, respectively, gave the bridgehead monocations 18 -Cl, 20 -Cl, and 13 -Cl, respectively.     

In situ-Erzeugung von [PX] und Insertion in (tBuP)3, (X = Cl,Br) Synthese der funktionalisierten Cyclophosphane (tBuP)3PX, [-(tBu)(X)P-2,3,4-(tBu)3]P4und Strukturbestimmung von (tBuP)3PCl

In situ Generation of [PX] and Insertion into (^tBuP)₃, (X = Cl, Br). Synthesis of the Functionalized Cyclophosphanes (^tBuP)₃PX, [1-(^tBu)(X)P-2,3,4-(^tBu)₃]P₄ and Structure Analysis of (^tBuP)₃PCl The redox system PX₃/SnX₂ (X = Cl, Br) can be used as a source for the in situ generation of halogenphosphanediyl [PX]. In the presence of tri-t-butylcyclotriphosphane (^tBuP)₃ the intermediately formed [PX] is added to a ring P atom followed by an insertion reaction, which leads to a ring expansion, whereby monohalogenocyclotetraphosphanes (^tBuP)₃PX (X = Cl, Br; 1, 2 ) are formed. Excess [PX] does not lead to further ring expansion but through a complex reaction course to the functionalized cyclotetraphosphanes [1-(^tBu)(X)P-2,3,4-(^tBu)₃]P₄, 3 (X = Br); 7 (X = Cl). 1, 2 and 3 could be obtained in a pure form and NMR and mass spectroscopically, 7 ³¹P-NMR spectroscopically, characterized. For 1 and 7 ³¹P? ^35,37Cl-isotopic shifts could be identified. 1 was further characterized by an X-ray structure analysis.     

3-Ferrocenyl-3-(1-naphthyl)cyclopropene. Synthesis, structure, and chemical transformations

Crystalline 3-ferrocenyl-3-(1-naphthyl)cyclopropene was prepared by dehydrobromination ofZ- andE-2-bromo-1-ferrocenyl-1-(1-naphthyl)-cyclopropanes by Bu^tOK in DMSO. The resulting compound and the startingZ-monobromocyclopropane were characterized by X-ray diffraction analysis. The obtained cyclopropene reacts with 1,3-diphenylisobenzofuran to give a [4+2]-cycloadduct. The small ring opens upon treatment with HBF₄ etherate to afford isomericZ- andE-prop-1-enes and 1-ferrocenyl-3H-benzo[e]indene. Thermolysis of this cyclopropene results in the formation of 1-ferrocenyl-9bH-benzo[e]indene. In all cases, opening of the small ring is accompanied by exclusive alkylation of the naphthalene moiety. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 499–506, March, 1998.