Bicyclo decadiene

Based on a similar approach, Backvall403 established the stereochemical course of such reactions and developed efficient routes to bicyclo[4.3.0]-nonadiene and bicyclo[5.3.0]-decadiene systems. Backvall404 has also reported a Pd(02CCF3)2-catalyzed oxidative carbocyclization of allenenes (Scheme 125). The process is efficient even with catalyst loading as low as 1 mol%, although if requires/>-benzoquinone as the stoichiometric oxidant, which represents the first example of a C-C bond formation using a catalytic amount of Pd(ll). Bicyclic adducts have been obtained in... 

Representing an impressively straightforward route to bicyclo[5.3.0]decadiene derivatives, Martin and co-workers have designed a one-step route to the [5 + 2]-cycloadducts from alkynes and VCP building blocks through the use of a sequential [RhCKCO k-catalyzed allylic alkylation/[5 + 2]-cycloaddition (Equation (9)). 

In turn, the propensity of 1 to respond to steric hindrance can be used to control the site of initiation of an RCM reaction in a polyene substrate (Scheme 9) [20]. Thus, dienyne 25 reacts with the catalyst regioselectively at the least substituted site the evolving ruthenium carbene 26 undergoes a subsequent enyne metathesis leading to a new carbene 27, which is finally trapped by the disubsti-tuted olefin to afford the bicyclo[4.4.0]decadiene product 28. By simply reversing the substitution pattern of the double bonds, the complementary bicyclo [5.3.0] compound 32 is formed exclusively, because the cyclization cascade is then triggered at the other end of the substrate. Note that in both examples tri-substituted olefins are obtained by means of a ruthenium based metathesis catalyst [20] ... 

When the pyrone 297 was exposed to base in dichloromethane, formation of the oxidopyrylium occurs and subsequent cycloaddition transpires. Lee found that when the allene tether was 3 (n = 0), cycloaddition occurs to form the bicy-clo[5.3.0]decadiene 298 exclusively, rather than the alternative bicyclo[5.2.0] nonadiene product 299. Increasing the tether length by one resulted in formation of the exo-substituted double bond (299) in 45% yield. Increasing the tether length by one carbon, to four, completely retarded the cycloaddition (Scheme 4.83). 

Similarly, the intramolecular alkylation of lithium 3-(4-camphorsuIfonyloxybutyl)-2,4,6-trimeth-ylphenolate using potassium tert-butoxide as base, leads under reflux to bicyclo[4.4.0]decadiene derivatives5,6. 

Bicyclic cyclotrigermanes, thermolysis, 3, 793 Bicyclic imidazoles, via intramolecular C-H functionalizations, 10, 138 Bicyclic siloxanes, rational synthesis, 3, 655 Bicycloctasilane dianion, preparation, 3, 466468 Bicyclo[5.3.0]decadiene, via [5+2]-cycloadditions, 10, 613 Bicyclo[5,3,0]-decanes, via Pauson-Khand reaction, 11, 361 Bicyclononasilane anions, preparation, 3, 466-468 Bicyclo[3.3.0]-octanones, via carbonylative carbocyclization, 11, 427... 

Treatment of the bicyclogermacrene (89 equation 32), containing a cyclopropane ring, with dilute sulfuric acid leads to the aromadendrene (90 cf. guaiane 74), together with the bicyclo[4.4.0]decadiene... 

Am Bicyclo[4.4.0]decadien-(1,3) laufen bcidc Reaktionstypen gleiehzeitig ab1, so daB Tricyclo[4.4.0.01 i]decen-(2) und l-Butadien-(l,3)-yl-cyclohexen gebildet werden ... 

Trimethylsilyl)diazomethane was also applied successfully to the total synthesis of pinguisane-type sesquiterpenes for the ring expansion (9-12) of the bicycloocte-none 9.16 by Uyehara et al. (1986). The same authors used (trimethylsilyl)diazome-thane for the ring expansion of the bicyclic ketone 9.17 (9-13) in studies on the synthesis of the novel sesquiterpenoid ( ) nakafuran-8, a bicyclo[4.2.2]decadiene with antifeedant properties (Uyehara et al., 1992). 

Subsequently partial hydrogenation of trans,trans- and of cw,c/ -2,8-decadiene-4,6-diyne over a Lindlar catalyst resulted in trans- and cw-7,8-dimethyl bicyclo[4.2.0]octa-2,4-diene, respectively (Scheme 9.48). " ... 

The purely thermal processes that are involved include the formation of cw-9,10-dihydronaphthalene (C9,10) from bullvalene (BV), bicyclo[4.2.2]decatetrene (422) and its intramolecular Diels-Alder adduct, tetracyclo[4.4.0.0 0 ]decadiene (TCD), from lumibullvalene (LBV), isobullvalene (IBV), tricyclo[5.3.0.0 ]deca-3,5,9-triene (TDT), and isolumibullvalene (ILBV), from basketene (BSK), NHC, TRQ, and the syn and anti isomers of tricyclo[4.4.0.0 ]decatriene (S and A, respectively), and from all c/ -cyclodecapentaene (C5), snoutene (SNT), and diademane (DIA). A more recent review includes many heats of formation and enthalpies of activation ... 

Brase and coworkers [29] also reported highly enantioselective desymmetrization of rran5-bicyclo[4.4.0]decadienes 81-84, which were prepared through Birch reduction of naphthalene, epoxidation and epoxide-opening reaction (Figure 13.11). The position of C=C double bonds also differed from the previous report [25], Although a Mizoroki-Heck reaction of aryl iodide 81 with the usual chiral ligands such as BINAP, DIOP i(2R,3R)- or (25,35)-0-isopropylidene-2,3-dihydroxy-l,4-bis(diphenylphosphino)butane)... 

For one recent example, see Lormann, M.E.P., Nieger, M. and Erase, S. (2006) Desymmetriza-tion of bicyclo[4.4.0]decadienes a planar-chiral complex proved to be most effective in an... 

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