Bicyclo octane, reaction with

Bicyclo[2.2.1]hepta-2,5-diene, nitrosyl chloride adduct, 46, 74 reaction with acetic acid to yield nortricyclyl acetate, 46, 74 Bicyclohexyl, 46, 61 Bicyclohexylidene, 47, 34 ejSO-e s-BlCYCLO[3.3.0]OCTANE-2-CAR-BOXYLIC ACID, 47, 10 Bicyclopentadienylidene, octa-chloro-, 46,93... 

A bicyclic peroxide was isolated in 1.8% yield by HPLC of the bromodemercuration product, and was identified as a single diastereoisomer of 2,4-dibromo-6,7-dioxa-bicyclo[3,2.1]octane 57 with the iransjrans- or cis,cis-configuration. By analogy with the cyclooctadiene reactions, formation of the other two diastereoisomers of 57 can be expected, but although additional peroxides with similar HPLC characteristics were detected, they were not identified. Thus the presence of [2.2.2]-compounds cannot be ruled out, and no comment can be made on the regioselectivity of the dioxabicyclization. 

In the preparative application of [2 + 2]-photocycloadditions of cyclic enones to (substituted) alkenes, two factors concerning product formation are of decisive relevance, namely the regioselectivity and the (overall) rate of conversion. Regarding the regioselectivity in the addition to mono- and 1,1-disubstituted alkenes, Corey had shown that the preferred addition mode of cyclohex-2-enone to isobutene or 1,1-dimethoxyethylene was the one leading to—both cis- and trans-fused—bicyclo[4.2.0]octan-2-ones with the substituents on C(7) [8]. In contrast, in the reaction with acrylonitrile, the alternate orientation was observed to occur preferentially. Similar results were also reported by Cantrell for the photocycloaddition of 3-methyl-cyclohex-2-enone to differently substituted alkenes [14]. No significant differences in the overall rates of product formation for the different alkenes were observed in these studies. In order to explain these observed... 

Upon reaction with the Simmons-Smith reagent104) or m-chloroperbenzoic acid,105 cyclooctyne is transformed at least in part to products of the bicyclo-[3.3.0]octane type. 

The Simmons-Smith reagent undergoes a transannular reaction with cyclooctyne to give bicyclo[3.3.0]octane derivatives (547a). The reaction... 

The rearrangement of isopent-3-enyl epoxy esters with Cp2ZrCl2/AgC104 yields asymmetric bicyclo octane esters which are base-stable protecting groups for carboxylic acids (Scheme 48). However, the orthoesters are only the kinetic products and can rearrange under reaction conditions to more stable THF derivatives. 

DCP as a Chiral Controller in Oxidative Free Radical Cyclizations. As a chiral auxiliary, DCP (1) is also reported to induce modest diastereoselection (60% de) in Mn(III)-based oxidative free-radical cyclizations of p-keto esters (eq 12). Chiral p-keto ester 25 was prepared by transesterification reaction with methyl ester 23, 1, and 0.3 equiv of DMAP (catalyst) in anhydrous toluene at reflux for 3-5 d as described by Taber. Oxidative cyclization of a 0.1 M solution of 24 in AcOH with 2 equiv of Mn(OAc)3-2HzO and 1 equiv of Cu(OAc)3 HzO provided bicyclo[3.2.1]octan-2-one (25). 

Reaction. with Lithium Thiocyanate. To LiSCN (153 mg, 2.3 mmol) in anhyd Et O (1 mL) was added exo-7,8-epoxybicyclo[4.2.0]octane (166 mg, 1.3 mmol). The flask was stoppered and stirred at 4L C for 34 h. Workup as described above gave the product yield 150 mg (90%), whose H NMR spectrum was consistent with that of known bicyclo[4.1.0]heptane-en<7o-7-carbaldehyde and displayed no cxo-aldchyde signal at 5 = 9.1. Air oxidation of the carbaldehyde gave an acid identical with authentic bicyclo[4.1.0]hep-tane-enrfo-7-carboxylic acid. ... 

The reaction of bicyclo[4.1.0]heptane with diborane and subsequent treatment with hydrogen peroxide produced predominantly cyclohexylmethanol (5b) in high yield.Under modified experimental conditions small amounts of isomeric methylcyclohexanol (6b) and cycloheptanol (7b) were isolated. In contrast to the hydroboration of alkenes, the cyclopropane cleavage reaction is inhibited by ethereal solvents such as diethyl ether, tetrahydrofuran or 2-methoxy-ethyl ether. Bicyclo[3.1.0]hexane reacted with diborane in a similar fashion to give mainly cyclopentylmethanol (5a).The reaction of l-methylbicyclo[4.1.0]heptane gave a mixture of cis- and tram-(2-methylcyclohexyl)methanol (5c) in an initial ratio of 60 40. Spiro[2.5]octane reacted with diborane to yield only products derived from scission at the spiro carbon. The main product was 2-cyclohexylethanol (8). ... 

Gandolfi, C., Pellegata, R., Ceserani. R.. and Usardi, M.M., co-iVor-cycloalkyl-13,14-dehydroprostaglan-dins, Farmitalia Carlo Erba, German Patent Appl. DE 2539116, 1976 Chem. Abstr, 85, 77748, 1976. Braun, N.A., Klein, I., Spitzner. D.. Vogler, B., Braun, S., Borrmann, H., and Simon, A., Cascade reactions with chiral Michael acceptors. Synthesis of enantiomerically pure tricyclo[3.2.1.0 - ]- and bicyclo[3.2.1]octanes, Liebigs Ann. Org. Bioorg. Chem., 2165, 1995. 

Rehwinkel, H., Skupsch, J., and Vorbrtiggen, H., E- or Z-selective Homer-Wittig reactions of suhsti-tuted bicyclo[3.3.0]octane-3-ones with chiral phosphonoacetates. Tetrahedron Lett., 29, 1775, 1988. Tiillis, J.S., Vares, L., Kann, N., Norrby, P.-O., and Rein, T., Reagent control of geometric selectivity and enantiotopic group preference in asymmetric Horner-Wadsworth-Emmons reactions with meso-dialdehydes, J. Org. Chem., 63, 8284, 1998. 

Hydroxy, methoxy, or acetoxy groups in the bridgehead carbon atom of the bicyclo[2.2.2]octane series can often be replaced by reaction with a halogenating... 

It was characterized by chemical analysis, ozonolysis to form formaldehyde, hydrogenation, bromination and by its infrared and 1H-NMR spectra. The diene has also been prepared by pyrolysis of l,4-bis-(acetoxymethyl)cyclohexane (13,14), from cyclohexanedione by the Wittig reaction (11,15) or by reaction with diazomethane (16), and by the electrochemical or metal reduction of 1,4-dihalo-bicyclo-[2,2,2-]octanes (17,18) or of l,l,2,2-tetrakis-(bromo-methyl)-cyclobutane (19). It is very stable if stored in ammonia rinsed, dry flasks. 

An interesting new approach to monoterpene pyridine alkaloids has been described recently by Vidari and co-workers (206), based on the ability of a Schmidt reaction to desymmetrize bicyclo[3.3.0]octane-3,7-dione (249). This was achieved through reaction with sodium azide and boron trifluoride in CH2CI2 H20 (1 1) at 25°C for 3 h, which gave the lactam 250 in 25% yield. This could be increased to 50% yield by reacting 249 with sodium azide and cone. HC1. Ketalization followed by N-methylation with a phase transfer catalyst gave the lactam 251. Monomethylation of 251 afforded... 

A cyclooctane system with two exomethylene units can be cyclized in refluxing water. This type of reaction leads exclusively to a cw-bicyclo[3.3.0]octane skeleton with two quaternary bridgehead carbon atoms20. 

The silyl-bridged four-membered rings are not A, B observed in these reactions with aminofluorosilyl-substituted rings. These Li salts react by one route to triply substituted products they also form bicyclo[4.2.0]octanes by an intramolecular reaction with LiF elimination and silyl group and methanide ion migration . Figure 4 shows the structure of compound... 

Similarly, bicyclo[2.2.2]octane yields a mixture of acetamides in yield (75%) on reaction with NO2 BF4 in acetonitrile. 

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