Bicyclo 5-methyl

As described in Section 1.7.1, the utility of the Wenker reaction is limited to substrates without labile functionalities because of the involvement of strong acid and then strong base. The Fanta group prepared a variety of aziridines by taking advantage of the Wenker reaction.For example, 6-aza-bicyclo[3.1.0]hexane (14) was produced from the ring-closure of ( )-rra s-2-aminocyclopentanol hydrochloride (13). In a similar fashion, sulfate ester 16 was prepared from A-methyl dl-trans- >-ssmnoA-hydroxytetrahydrofuran (15). Subsequent treatment of sulfate ester 16 with NaOH then delivered aziridine I . " Additional examples of Wenker aziridine synthesis may also be found in references 15-17. 

When formation of either the five- or six-membered ring was possible for N-chloroamine 37, only the five-membered ring was conducive under the Hofmann-Ldffler-Freytag reaction conditions, forming exclusively 6-ethyl-6-aza-bicyclo[3.2.1]-octane (38). No 2-ethyl-2-aza-bicyclo[2.2.2]-octane (39) was observed. On the other hand, 2-methyl-2-aza-bicyclo[2,2.2]octan-6-one (41) was installed by UV irradiation of a solution of A -chloroamine 40 in TFA. Ironically, when the ketone functionality on 40 was protected as its ethylene ketal group, the resultant steric interactions completely prohibited the classic Hofmann-Loffler-Freytag reaction. 

Abbreviations acac, acetylacetonate Aik, alkyl AN, acetonitrile bpy, 2,2 -bipyridine Bu, butyl cod, 1,5- or 1,4-cyclooctadiene coe, cyclooctene cot, cyclooctatetraene Cp, cyclopentadienyl Cp, pentamethylcyclopenladienyl Cy, cyclohexyl dme, 1,2-dimethoxyethane dpe, bis(diphenyl-phosphino)ethane dppen, cis-l,2-bis(di[Atenylphosphino)ethylene dppm, bis(diphenylphosphino) methane dppp, l,3-bis(diphenylphosphino)propane eda,ethylenediamine Et,ethyl Hal,halide Hpz, pyrazole HPz, variously substituted pyrazoles Hpz, 3,5-dimethylpyrazole Me, methyl Mes, mesityl nbd, notboma-2,5-diene OBor, (lS)-endo-(-)-bomoxy Ph, phenyl phen, LlO-phenanthroline Pr, f opyl py, pyridine pz, pyrazolate Pz, variously substituted pyrazolates pz, 3,5-dimethylpyrazolate solv, solvent tfb, tetrafluorobenzo(5,6]bicyclo(2.2.2]octa-2,5,7-triene (tetrafluorobenzobanelene) THE, tetrahydrofuran tht, tetrahydrothicphene Tol, tolyl. 

Chemical Name 7-[ [Amino-(4-hydroxyphenyl)acetyl] amino] -3-methyl-8oxo-5-thia-1 -aza-bicyclo [4.2,0] oct-2-ene-2-carboxylic acid monohydrate... 

The enantiomerically pure isobomeol allyl sulfoxide derivatives (17 ,2Y,3/ ,4S )-1,7,7-tri-methyl-3-[(S)- or -(/ )-2-propenylsulfmyl]bicyclo[2.2.1]heptan-2-ol are thermally more stable inversion of configuration at sulfur, S -> / , occurs at 135-145 °C. Their lithio derivatives give exclusively y-1,4-adducts with 2-cyclopentenone19. 

Using 3-substituted cyclohexanones the /rans-diastereoselective synthesis of decalones and octahydro-1 //-indenones may be achieved 164 169. This method has been applied, for instance, in the synthesis of 19-norsteroids. In a related Michael addition the lithium enolate of (R)-5-trimethylsilyl-2-cyclohexenone reacts with methyl 2-propenoate selectively tram to the trimethylsilyl substituent. Subsequent intramolecular ring closure provides a single enantiomer of the bicyclo[2.2.2]octane170 (see also Section 1.5.2.4.4.). 

The CM reaction between 2-methyl-2-butene (a gera-disubstituted olefin that served in this case also as solvent) and the allylated compound 300, possessing the bicyclo[3.3.1]nonane core of the potential Alzheimer therapeutic garsubellin A (302) [137], underlines the increased activity of the second-generation ruthenium catalysts (Scheme 58). In the presence of 10 mol% of NHC catalyst C, the prenylated compound 301 was formed after only 2 h in 88% yield. 

AuBerst selektive 1,2-Reduktionsmittel sind Bis-[2-methyl-propyl]-aluminiumhydrid1, Tris-[2-methyl-propyl]-aluminium2, Natrium-bis-[2-methyl-propyl]-dihydrido-aluminat3 und besonders 9-Bora-bicyclo[3.3. ljnonan4 (9-BBN, S. 7). Letzteres ergibt zuerst ein Alkoxy-boran, das zweckmaRig mit 2-Amino-athanol gespalten wird. 

Ct 0 COOCH3 NafBHJ 10-Hydroxy-1,6-di-methyl-2-methoxycarbonyl-bicyclo [4.4.0]decan 91 (F 71-74°) 2... 

N H3c —COO H3C-COO It 0 K[BH4] 3-Hydroxy-8-methyl-trans-6,7-diacetoxy-8-aza-bicyclo[3.2.1]octan 84 3... 

Zu einer Losung von 0,6 g (16 mMol) Natriumboranat in 30 ml Methanol und 6 ml Wasser tropft man eine Losung von 0,7 g (2,3 mMol)4-Tosyloxy-2-oxo-l-methyl-bicyclo[2.2.2]octan in 90ml Methanol, riihrt 24 Stdn. bei 20°, gibt 300 ml ges. Calciumchlorid-Losung hinzu, schiittelt mit Petrolather aus, trocknet iiber Natriumsulfat und destilliert Ausbeute 0,3 g (95% d.Th.) Kpi, 108°. 

Unter milden Bedingungen reduzieren 9-Alkyl-9-bora-bicyclo[3.3.1]nonane Aldehyde zu Alkoholen3. Dabei muB die mit dem 9-[3-Methyl-butyl-(2)]-Derivat entstehende 9-Alkoxy-Verbindung durch Zugabe von 2-Amino-athanol zersetzt werden. 

Bei der elektrochemischen Reduktion von Cycloalkanonen steht i. a. der stereochemi-sche Aspekt (cis/trans axial/aquatorial) im Vordergrund, so z. B. bei der Reduktion der Methyl- und anderer Alkyl-cyclohexanone, substituierter 2-Oxo-bicyclo[2.2.1]heptane und bei Oxo-dekalinen. Mit zumeist Alkoholen als Solvens fallen die entsprechenden cy-clischen sekundaren Alkohole zu 47-60% d.Th. an7-11. 

Bei der Elektrolyse von 1-Acetyl-naphthalin in 2 n athanol. Kalilauge wird 59% d.Th. 9-Methyl-9-naphihyl-( 1 )-6-acetyl- (benzo-6-oxa-bicyclo[3.2.1 ]octen-(2)) erhalten2 ... 

Auf analoge Weise erhalt man galvanostatisch (200 mA) aus 5-Oxo-cycloocten 1-Hydroxy-bicyclo[3.3.0 pctan (69% d. Th.) bzw. aus 2-[Buten-(3)-yl]-cyclohexanon 1-Hydroxy-9-methyl-bicyclo[4.3,0]nonan (67% d. Th.)2 ... 

Die kathodische Reduktion von l,4-Dibrom-bicyclo[2.2.1]heptan in DMFergibt neben Bicyclo[2.2.1]nonan (I) und Pentacyclo 4.2.2.22 sl1,bl2 s]tetradecan (II) 1-(N-Methyl-N-formyl-amino)-bicyclo[2.2.1, ]heptan (III)4 ... 

Dioxo-6f -methyl-2-(2-carboxy-dthyl)-bicyclo[4.3.0] nonen-( 1 23°/() d.Th. 

Zur Reduktion von 3,7-Dioxo-6/3-methyl-2-(2-carboxy-athyl)-bicyclo[4.4.0]decen-( 1) s.S. 764. 

Beim 3,7-Dioxo-6-methyl-bicyclo[4.3.0]nonen-(l) vermag Curvularia falcata (Teflon) Boedijn bei Einhaltung bestimmter Bedingungen zwischen der (6R)- und der (6S)-Form zu unterscheiden3 (nur das 5-Derivat wird reduziert) ... 

Dioxo-6-methyl-2-(2-carboxy-athyl)- 722 Bicyclo[4.3.0]nonadien-(3,7)... 

Methyl-2-(4-brom-N-methyl-anilinomethyl)- 661 Bicyclo[3.3.1 ]nonan... 

It is interesting to note that the parent dienone 67 and its 2-methyl derivative 68, when irradiated in strongly acidic media, gave no product which would con espond to the protonated bicyclo[4,l,0]heptenone observed in the photolysis of protonated eucarvone. In FHSO3 at — 66°... 

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