Bicyclo nonane, preparation

Pinene is an important auxiliary for directed chiral syntheses. It has been used for preparation of mono- and diisoplnocampheylborane5 B-al lyldiisopinocampheylborane,6 B-pinanyl-9-bora[bicyclo]nonane, cis-... 

In an effort to delineate these effects, the ratio of 1,5-cis to 1,5-trans products in fused bicyclo[4.3.0]nonanes prepared by the radical cyclization of axially and equatorially oriented 2-but-3-enylcyclohexyl radicals, which are conformationally locked, was studied [14]. These results are shown in Figs. 7.13 and 7.14. 

Studies by the submitters have indicated that the procedure reported here is the preferred method for the preparation of bicyclo[3.2.1]octan-3-one. It employs readily available, inexpensive reagents, and the overall yield is good. In addition, the method can be used for the synthesis of the difficultly accessible next higher homologues of bicyclo[2.2.2]oct-2-ene as well as for derivatives of norbornene. Bicyclo[3.2.2]nonan-3-one and l-methylbicyclo[3.2.1]octan-3-one have been prepared by a similar route6 in 60% and 47% yields, respectively (based on adduct). However, the preferred procedure for the formation of the dichlorocarbene adduct of bicyclo[2.2.2]oct-2-ene is that of Seyferth using phenyltrichloromethylmercury. Even in this case the overall yield is moderate (37%). 

Introduction of the allene structure into cycloalkanes such as in 1,2-cyclononadiene (727) provides another approach to chiral cycloalkenes of sufficient enantiomeric stability. Although 127 has to be classified as an axial chiral compound like other C2-allenes it is included in this survey because of its obvious relation to ( )-cyclooctene as also can be seen from chemical correlations vide infra). Racemic 127 was resolved either through diastereomeric platinum complexes 143) or by ring enlargement via the dibromocarbene adduct 128 of optically active (J3)-cyclooctene (see 4.2) with methyllithium 143) — a method already used for the preparation of racemic 127. The first method afforded a product of 44 % enantiomeric purity whereas 127 obtained from ( )-cyclooctene had a rotation [a]D of 170-175°. The chirality of 127 was established by correlation with (+)(S)-( )-cyclooctene which in a stereoselective reaction with dibromocarbene afforded (—)-dibromo-trans-bicyclo[6.1 0]nonane 128) 144). Its absolute stereochemistry was determined by the Thyvoet-method as (1R, 87 ) and served as a key intermediate for the correlation with 727 ring expansion induced... 

Heteroatoni groups such as boron or silicon can activate or direct synthetic reactions. Use of such activation has become of major importance in organic syntheses. Examples in this volume are BORANES IN FUNCTIONALIZATION OF DIENES TO CYCLIC KETONES BICYCLO[3.3.1]NONAN-9-ONE and BORANES IN FUNCTIONALIZATION OF OLEFINS TO AMINES 3-PINANAMINE. Use of trimethylsilyl or trimethyl-silyloxy groups to activate a 2-butenone or a butadiene are illustrated by the preparations 3-TRIMETHYLSILYL-3-BUTEN-... 

Bridged systems can also be prepared in high yield by this process.84 For example, treatment of the keto diester (348 Scheme 43) with (61) in basic DMSO gave a 41% yield of the diketo diester (352) by way of the intermediates (349) to (351), involving two Michael additions and final Dieckmann condensation.84 Similar processes have also been used to make other bicyclo[3.3.1]nonanes and related com-... 

The authors reported the chiral separation of proline and thereonine amino acid up to 20 and 6g, respectively, in a single run. Micropreparative resolution of lecucine was presented. The resolution was discussed with respect to the degree of sorbent saturation with copper(II), elution rate, eluent concentration, temperature, and column loading condition [16]. Weinstein [74] reported the micropreparative separation of alkylated amino acids on a Chiral ProCu column. In another article, a preparative chiral resolution of 3-methylene-7-benzylidene-bicyclo[3.3.1]nonane was achieved on 7.5% silver(I)-d-camphor- 10-sulfonate CSP [75]. Later, Shieh et al. [71] used L-proline-loaded silica gel for the chiral resolution of (ft,5 )-phcnylcthanolaminc as the Schiff base of 2-hydroxy-4-methoxyacetophenone. Gris et al. [76] presented the preparative separations of amino acids on Chirosolve L-proline and Chirosolve L-pipecolic acid CSPs. 

The most intriguing, and apparently general reaction for the preparation of dehydrohomoadamantanes involves the (2+2) cycloaddition of 3,7-di-methylene-bicyclo[3.3.1]nonane. Photolysis of the parent diene gives 3,6-dehydrohomoadamantane which, upon reaction with bromine, gives 1-bromo-3-bromomethyladamantane (Eq. (44))136). Thermodynamic control un-... 

Lithium dialkyl-9-borabicyclo[3.3.1]nonane ate complexes react with acetyl chloride via hydride transfer to form cz. s-bicyclo[3.3.0]oct-1 -yldialkylboranes.11 The conversion of B-methyl-9-BBN to 63 upon sequential treatment with methyl-lithium and acetyl chloride (93 % yield) illustrates the procedure. As shown in Scheme 17, these organoboranes can serve as valuable intermediates for the preparation of a variety of 1-substituted [Pg.62]

Target selection and synthetic strategy in solution Compound 3.25 contains a condensed lactone and a selenium-based substituent appropriate transformations of the two groups should give access to diverse tricyclic compounds. A more radical decoration of the nucleus (3.28, Fig. 3.17) could reasonably be conceived to fuUy exploit the bicyclo[3.3. l]nonan-9-one nucleus. Literature search found arelated approach (22) where a similar, less congested tricyclic nucleus 3.29 was prepared by selenium-... 

There have been relatively few applications to the contraction of larger rings. Irradiation of solutions of 4-diazo-/ra j-bicyclo[6.1.0]nonan-5-one afforded the strained carboxylate derivatives (107 XR = OH, OMe) in ca. 22-45% yield.Small to medium ring diazo ketones afford the ring-contracted carboxylic acids (108 n = 4-10) in 25-95% yield on photolysis in dioxane-H20 or THF-H20. Thermolysis of the diazo ketones in aniline at 150-160 C gave the anilides of (108) in 78-91% yield. Transannular reactions of the ketocarbene intermediates can be a complication under some conditions. 4-Carboxy[8]paracyclophane (109) has been prepared (25%) by the photochemical method. ... 

In refluxing cyclooctene, exo-7-bromo-c t/f>-7-(trimethyistannyl)bicyclo[4.1.0]heptane (20) reacted via the corresponding cyclopropylidene intermediate to afford spiro[bicyclo[4.1.0]hep-tane-7,9 -bicyclo[6.1.0]nonane] (21) in 76% yield. However, this reaction is not preparatively interesting and not applicable to a-bromo-a-(trimethylstannyl)cyclopropanes in general, because the cyclopropylidenes from the latter gave ring-opened allenic products. ... 

Tandem reactions have emerged as promising procedures for the synthesis of highly functionalised compounds in a single step. Horner-Wadsworth-Emmons reactions have been coupled with 1,4-Michael additions to prepare 6-substituted a,p-unsaturated carboxylic acids derivatives, and with Diels-Alder reactions, which utilised sugar-derived phosphonate (176) to prepare enantiomerically pure bicyclo[4.3.0]nonanes. ... 

When dihalo-bicyclo[n.l.O]alkanes are solvolyzed, ring-enlargement products are formed. In fact, this reaction is often the method of choice for the preparation of medium-sized rings. As far as the stereochemical outcome of the reaction is concerned, there are conflicting reports in the literature. Thus a mixture of ( )-and (2>-2-bromocyclononenols has been obtained by solvolysis of 9,9-dibromo-bicyclo[6.1.0]nonane [169] in earlier reports only the (Z)-diastereomer was mentioned [170], and the solvolysis in aqueous a< one in the presence of silver tosylate apparently provides only the ( )-isomer [171]. 

Polymerization of Bicyclo[n. 1.0]Alkanes. From the large-ring bicyclo[n.l.0]alkane series, six were chosen because of their relative ease of synthesis bicyclo[5.1.0]octane (M2), bicyclo[6.1.0]nonane (M3), bicyclo[ 10.1.0] tridecane (M4), and the corresponding 1-methylbicyclo-[n. 1.0] alkanes and prepared from the corresponding cycloalkenes or 1-methylcyclqalkenes (cycloheptene, cyclooctene, and cyclododecene). See Equation 4. 

The described reactions start from the compounds bis-9-bora-bicyclo[3.3.1]nonane (9H-9-BBN)2, elemental sulfur (Sg), and dihydrogen sulfide or from the easily preparable 9-iodo-9-borabicyclo[3.3.1]nonane. The procedures are simple and practicable, and the yields are nearly quantitative. The (9H-9-BBN)2-sulfur reaction can be followed not only by NMR spectroscopy but also by volumetric measurements of the evolved gas (H2). It is also remarkable that the BC bonds of the 1,5-cyclooctanediylboryl group are completely stable toward sulfidation at temperatures up to about 150 . The three compounds described here can be prepared easily on a scale of some 100 g of high purity. If necessary, the purification is possible, involving distillation or sublimation under vacuum without any decomposition. 

Preparation of enantiomerically active hydrocarbons is difficult and only a few examples of the preparation of chiral hydrocarbons have been reported. For example, chiral 3-phenylcyclohexene has been derived from tartaric acid through eight synthetic steps. Enantiomeric separation by host-guest complexation with a chiral host is more fruitful for the preparation of chiral hydrocarbons. For example, when a solution of fR,Rh( )-t ws-4,5-bis(hydroxydiphenylmethyl)-l,4-dioxaspiro[4.4]-nonane (lb) [2] (3 g, 6.1 mmol) and rac-3-methylcyclohexene (2a) (0.58 g, 6.1 mmol) in ether (15 ml) was kept at room temperature for 12 h, a 2 1 inclusion complex of lb and 2a (2.5 g, 75%) was obtained as colorless prisms in the yield indicated. The crystals were purified by recrystallization from ether to give the inclusion complex (2.4 g, 71%), which upon heating in vacuo gave (-)-2a of 75% ee by distillation (0.19 g, 71%) [3]. By the same inclusion complexation, (-i-)-4-methyl- (2b) (33% ee, 55%), (-)-4-vinylcyclohexene (2c) (28% ee, 73%), (-)-bicyclo[4.3]-nonane-2,5-diene... 

As a useful alternative to carbonylation, the Brown dichloro-methyl methyl ether (DCME) process has been effectively used for the synthesis of 9-alkylbicyclo[3.3.1]nonan-9-ols. 2 The ketone bicyclo[3.3.1]nonan-9-one (eq 29) has also been prepared from a hindered B-aryloxy-9-BBN derivative, with simple B-alkoxy-9-BBN derivatives failing to undergo this process. However, most borinate esters are smoothly converted to ketones through this process, including germa- and silaborinanes (eq 30). In these cases, 9-BBN-H provides the essential 1,5-... 

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