Bicyclo decanes synthesis

N,N -linked synthesis, 5, 269 6,6 -Biazulenes synthesis, 1, All Bibenzimidazolyls 3-oxides synthesis, 5, 412 1,1 - Bibenzimidazolyls synthesis, 5, 459 2,2 -Bibenzo[b]selenienyl synthesis, 4, 947 2,2 -Bibenzothiazolyl reduction, 6, 260 4,4 -Bichromenyl synthesis, 3, 743 Bicyclo[n. 1.0]alkanes retro-cycloaddition reactions, 1, 668 Bicyclo[5.3.0]decane synthesis, 1, 420 Bicyclo[4.1,0]diheteroheptanes synthesis, 3, 977... 

A synthesis of the highly functionalized tricyclic core of guanacasterpene represents an example of the Rh(i)-catalyzed intramolecular PKR leading to bicyclo[5,3,0]-decanes from the allenynes (Equation (50)). ... 

D. Batty and D. Crich, Acyl radical cyclizations in synthesis. Part 4. Tandem processes The l-endo/5-exo serial cyclizations approach to enantiomerically pure bicyclo[5.3.0]decan-2-ones, J. Chem. Soc. Perkin Trans 7 3193 (1992). 

Pyrolysis of the sodium salt of the tosylhydrazone of 10-bicyclo[5.2.1 ]deca-none provides a remarkably easy synthesis of tricyclo [5.2.1.0 4>10] decane... 

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... 

A good deal of effort has been devoted to the preparation of derivatives of the cyclohepta[cd]indole and bicyclo[4.3.1]decane ring systems, that can be considered related to the ABC and CD ring systems of welwistatin, respectively, but much of this work cannot be translated easily to methods relevant to welwistatin synthesis. For instance, many successful approaches to the cyclohepta[cd] indole system are based on intramolecular radical cycliza-tions [12] or Heck reactions [13]. In many published examples, a substituent at the indole C-2 avoids the competing reaction at this position, but this device renders the reaction products inadequate to achieve the oxindole struc-... 

The following references contain additional examples of this method and corresponding reaction types Synthesis of 3-fluoroethyl-2-cyclopenten-l-ones [35], preparation of functionalized bicyclo[5.3.0]decane systems and conversion of 1,2-divinylcyclopropanes to functionalized cycloheptanes [36] e.g. karaha-naenone [37], ( )-/Thimachalene [38][39]. Metal-catalyzed ring expansions in which cyclopropane (e.g. [40] [41] [42] [43] [44]) or aziridines (e.g. [45] [46]) and diaziridines (e.g. [45]) function as essential moieties are well known reactions. 

In summary, intramolecular reactions of a considerable variety of diones provide interesting mechanistic questions as well as a route forj construction of four- and five-membered rings in high photochemical and chemical yields. Except for a synthesis of cis- and trans-bicyclo[7.1.0]decan-2-one from cyclodecane-1,2-dione 122), this potential has been ignored. 

Naturally occurring compounds that possess as part of their structures bicyclo[5.3.0]decane and bicy-clo[5.4.0]undecane skeletons are very common in the terpenoid family of natural products. Since both of these carbon frameworks are readily prepared by sigmatropic rearrangement of 3-(2-vinylcyclopropyl) enones, it is not surprising that this method has been applied to the total synthesis of terpenoids. 

Witteveen JG, van der Weerdt AJA. Structure-odor relationships of some new synthetic sandalwood aroma chemicals. Synthesis and olfactive properties in a series of bicyclo(4.4.0.decan-3-ols. Rec. Trav. Chim. Pays Bas. 1987 106 29-34. 

J.K. Cha et al. developed a stereocontrolled synthesis of bicyclo[5.3.0]decan-3-ones from readily available acyclic substrates. Acyclic olefin-tethered amides were first subjected to the intramolecular Kulinkovich reaction to prepare bicyclic aminocyclopropanes. This was followed by a tandem ring-expansion-cyclization sequence triggered by aerobic oxidation. The reactive intermediates in this tandem process were aminium radicals (radical cations). The p-anisidine group was chosen to lower the amine oxidation potential. This substituent was crucial for the generation of the aminium radical (if Ar = phenyl, the ring aerobic oxidation is not feasible). 

The method of Huckin and Weiler has enjoyed widespread use in synthesis. For example, recently reported syntheses of rrans-bicyclo[4.3.1]decan-10-one and a bicyclo[4.4.1]undecan-7-one derivative have employed y-alkylations of 3-keto ester dianions as key steps. This methodology has also been extended to the formation and y-alkylation of dianions of y,8-unsaturated P-keto esters. ... 

A selection of examples (equations 24-31) demonstrate the considerable scope for transannular reactions of cyclodeca-l,S-dienes in the synthesis, including biomimetic synthesis, of a wide range of isomerically pure, substituted bicyclo[4.4.0]decanes. " ... 

On the basis of both synthetic and degradative studies, Marshall and co-workers have shown that the structure of -vetivone based on a bicyclo-[5,3,0]decane skeleton is untenable and subsequent work dictated the structure (326) incorporating a spiro[4,5]decane skeleton, and this they have confirmed by total synthesis. The method employed was the selective introduction of an isopropylidene group in a stepwise fashion starting with the keto-olefin (327), which was obtained via photolysis of the known dienone (328). 

A synthetically useful example of this process is the conversion of 117 to 120, which involves a 1,2-alkyl shift, and was part of Hwu s synthesis of (-)-solavetivone. 38 jhe alkyl fragment is actually part of the bicyclic ling system, one arm of the bicyclo[4.4.0]decane ring system. Reaction of the OH unit with the Lewis acid resulted in formation of the tertiary cation 118, which was followed by a 1,2-alkyls shift to give 119, where the new cation is stabilized by the adjacent silicon of the trimethylsilyl group. 39 Loss of the trimethylsilyl group from 119 gives spiran (120). 

The synthesis of appropriately functionalized bicyclo[4.3,0]decane derivatives continues to be a topic of current research. In this area, Heathcock et have published complete details of the syntheses and solvolyses of various 9-methyl-1-decalyl tosylates, a study which ultimately led to the obtention of bulnesol (291) and a-bulnesene (292). Similarly, Marshall and Greene have given a full account of their syntheses of guaio (293) and 7-epj-guaiol. Marshall et al ... 

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