Tricyclo heptenes

The reaction of morpholine with tricyclo[2.2.1.0 ]hcptan-3-one (35) and with 5-bicyclo[2.2.1]hepten-2-one (36) does not proceed in the... 

Homoconjugation results in enhanced reactivity of substrates toward ionic hydrogenation. Bicyclo[2.2.1]hepta-2,5-diene forms a mixture of the trifluoroac-etate esters of bicyclo[2.2.1]hepten-2-ol, tricyclo[2.2.1.02 6]heptan-3-ol, and bicyclo[2.2.1]heptan-2-ol in a 62 20 17 ratio on treatment with 10 equivalents of triethylsilane and 20 equivalents of trifluoroacetic acid for 24 hours at room temperature (Eq. 96), 230... 

This method constitutes a convenient synthesis of substituted tricyclo[2.2.0.02,6]hexane derivatives. It is surprising that the ring strain associated with these derivatives would permit their preparation at such high temperatures. A homologous reaction involves the intramolecular [2 + 2] cycloaddition of 2-vinylphenyl substituted cyclopropenes 5 which give benzotricy-clo[3.2,0.02,7]heptenes 6.74 This reaction also proceeds by sensitized photolysis but gives a more complex mixture. 

Pyrazoles 3 also undergo Diels-Alder addition with cyclobutadiene to give 116 (Scheme 29), which provides a ready entry into the trans-tricyclo[4.1.0.O J-S-heptene system 117.17,18,78,79 Where R2 and R3 are different, R3 is the more bulky.18... 

Tricyclo 5.2.1.02,6 decan 4-Methylen- E17c, 2238 (Methylen-cyclopropan + Bicyclo[2,2.1]hepten) exo- E21c, 3026 (bicycl. En -> Methylen-cyclopropan) Tricyclo]3.2.0.02,4]hept-6-en ... 

Two laboratories5,6 simultaneously reported the synthesis of the valence isomer of pleiadiene (14), namely naphtho[l,8]tricyclo[4.1.0.02, ]heptene (13), by the reaction of the lithium anion of phenalene (11) with methylene chloride and n-butyllithium at low temperatures. A mixture of (13) and (14) is obtained in the ratio of 4 1. The new hydrocarbon (13, m.p. 76-78°) is surprisingly stable, but when heated at 150° in cyclohexane... 

A number of bromocyclopropanes which also contain an electrophilic center in the molecule, undergo intramolecular substitution under the right conditions. When l-bromo-7-(3-chloro-propyl)tricyclo[4.1.0.0 ]heptane was reacted with butyllithium, tetracyclo[5.3.0.0 .0 ]de-cane (10) was obtained in 52% yield.Under similar conditions several substituted 7-bromo-bicyclo[4.1.0]heptene anti-epoxides and other epoxides were converted to polycyclic alcohols which result from intramolecular attack of the cyclopropyl anion on the oxirane ring. ... 

Acetophenone sensitized irradiation of bicyclo[2.2.1]hepten-2-ones 27 affords tricyclo-[3.1.1.02,6]heptan-3-ones 28. 

Dichlorocarbene. Tricyclo[3.2.1.015]octane (3) has been prepared from bicyclo[3.2.0]heptene-l(5) (1) as shown. The normal tetrahedral arrangement about the bridgehead carbons in (3) is impossible even so, (3) is remarkably stable the half-life at 195° is more than 20 hours. ... 

Bicycle [2.2.1 ]hepten 3,8 g 6,6 g Bcnzo-phenon in Benzol 450 W Hg- Brenner Pyrex-Filter 12 Stdn. c6hs 4,4-Diphenyl-3-oxa-exo-tricyclo [4.2.1.0W nonan 81 124-125 1,2... 

Maleinsaure-anhydrid -1- Bicyelo [2.2.1]hepten 1,17 g +5,0 g 0,58 g Benzophenon 130 ml CH2CI2 Hanovia 450 W Pyrex-Filter 4,5 Stdn. exo-Tricyclo [ 4.2.1.02.6] nonan-anti-3, anti-4-dicar-bonsaure-anhydrid + endo-Tri-cydo... 1... 

Die entsprechendeUmsetzungvonendo-5 - [2-Hydroxy-propyl-(2 )]-bicyclo [2.2.1] hepten-(2) verlauft sogar mit 85%iger Ausbeute zu 4A-DimefJiyl-3-oxa-tricyclo 3.2.1.P e ] nonan, obwohl bei einem tertiaren Alkohol geringerc Ausbeuten zu erwarten gewesen waren. Bei der saurekatalysierten, nicht photochemischen Reaktion addiert sich der Alkohol an das andere Kohlenstoff-Atom der Doppelbindung. 

Intramolecular cyclization of carbenoids. The most efficient route to the tricyclo[4.1.0.0 ]heptene-3 ring system (e.g., 3) is the methyllithium-promoted cyclization of a 7,7-dibromobicyclo[4.1.0]heptene-3 such as 2. The precursors (2) are available by dibromocarbene addition to 1,4-cyclohexadienes (1). The cyclization involves generation of a carbenoid and intramolecular C—H insertion. 

Bicyclo[3.2.0]hepta-2,6-diene Degenerate Rearrangement and Isomerization to 1,3,5-Cycloheptatriene Tricyclo[4.1.0.0 ]heptene 180... 

The oxymercuration of 1-substituted (i,e, H, Me, and C02Me) tricyclo[4,l,0,0 ]-heptanes with mercuric acetate affords norcaranyi- and norpinyl-mercury compounds. A synthesis of 3,4-benzotricyclo[4,l,0,0 ]heptene (692) has been reported in which the usual cyclopropylcarbene C—H insertion process is employed. Isomerization of (692) with silver perchlorate gave benzocycloheptatriene which is also formed in the thermal isomerization of (692). Reaction of (692) with n-ally 1 palladium(ii) chloride dimer yielded 2-methylene-l T-naphthalene which rearranged readily to 2-methylnaphthalene at room temperature a carbenoid mechanism appears to be involved. 

P-hydrogen. 1-Phenylbicyclopentane rearranged to 3-phenylcyclopenene in the presence of Znl2. Tricyclo[3.2.0.0 A] heptane 20 and tricyclo [3.1.0.0 ] hexane 21 were converted into bicyclo [3.2.0] heptene 22 and cyclohexa-1,3-diene 23, respectively, using AgBF [34]. 

The carbanionic centre which effects the intramolecular displacement in some 1,3-eliminations may be formed by addition of a carbanion to a double bond rather than by proton abstraction. Thus hydride reduction of the ditosy-late (33) gives a bicyclo[4,l,0]heptene and a tricyclo[5,1,0,0 ] octane as well as the direct displacement product. But in order to obtain other than the monocyclic product, it is necessary that the LiAlH4 be partially deactivated either by long storage or by addition of aluminium trichloride. 

Organomagnesiums and organolithiums add both cleanly in a cis- or yw-selective manner onto cyclopropenes. The especially tortured double bond of tricyclo[4.1.0.0 ]hepten-l(7)-en (131) behaves in the same way (Scheme 1-97). " ... 

---