Bicyclo hexane-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. 

Figure 4. Products of acetolysis of bicyclo[2.1. l]hexane-5-methyl tosylates.

Azatricyclo[2.2.1.02 6]hept-7-yl perchlorate, 2368 f Azetidine, 1255 Benzvalene, 2289 Bicyclo[2.1.0]pent-2-ene, 1856 2-/ert-Butyl-3-phenyloxaziridine, 3406 3 -Chloro-1,3 -diphenyleyclopropene, 3679 l-Chloro-2,3-di(2-thienyl)cyclopropenium perchlorate, 3388 Cyanocyclopropane, 1463 f Cyclopropane, 1197 f Cyclopropyl methyl ether, 1608 2,3 5,6-Dibenzobicyclo[3.3.0]hexane, 3633 3,5 -Dibromo-7-bromomethy lene-7,7a-dihy dro-1,1 -dimethyl-1H-azirino[l,2-a]indole, 3474 2.2 -Di-tert-butyl-3.3 -bioxaziridinc, 3359 Dicyclopropyldiazomethane, 2824 l,4-Dihydrodicyclopropa[ >, g]naphthalene, 3452 iV-Dimethylethyl-3,3-dinitroazetidine, 2848 Dinitrogen pentaoxide, Strained ring heterocycles, 4748 f 1,2-Epoxybutane, 1609 f Ethyl cyclopropanecarboxylate, 2437 2,2 -(l,2-Ethylenebis)3-phenyloxaziridine, 3707 f Methylcyclopropane, 1581 f Methyl cyclopropanecarboxylate, 1917 f Oxetane, 1222... 

Die Umlagerung von Cyclopenten-2-yl-methyl-Derivaten (59), (60) zu Bicyclo(3.1.0)hexan-2-yl-Verbindungen (61) konnte bei Desaminierung, Methanolyse, Acetolyse und Hydrolyse nachgewiesen warden 38). 

Die Solvolyse von Bicyclo(3.1.0)hexan-l-methyl-p-nitrobenzoat (158) wurde von Closson-and. Kwiatkowski untersucht (118), und dabei uberwiegend das 3-Methylen-cyclohexanol (159) gefunden. (158) reagiert 600mal schneller als... 

Analog erhalt man an Aluminiumoxid 2-Chlor-2-methyl-l-aza-bicyclo[2.1.1]hexan (70%) und 6-Chlor-I-aza-bicyclo[2.2.1]hept-2-en (70%)3 ... 

Although it is generally agreed that the thermal isomerization of bicyclo[2.2.0]hexanes to hexa-l,5-dienes takes place via diradical intermediates,113 118 121,123 125 experimental evidence has been obtained which implies otherwise.115,116 While a radical stabilization energy of approximately 4 kcal mol"1 was obtained for the pyrolysis of methyl 4-chlorobicy-clo[2.2.0]hexane-l-carboxylate (28 b) to methyl 5-chlorohexa-l,5-diene-2-carboxylate (29b),115116 as related to the parent 2-chlorohexa-1,5-diene (29a),115-l16-118 kinetic studies have indicated that there is a small but significant increase in activation energy of about 1 kcal mol-1 for the gas-phase and solution pyrolysis of l-chloro-4-methylbicy-clo[2.2.0]hexane (28c), as compared to l-chlorobicyclo[2.2.0]hexane (28a).115-116 In the light of this result, the commonly accepted diradical mechanism must be questioned and it is likely that the isomerization of these compounds occurs via a concerted process. 

Benzophenanthrene Benzyl bromide Benzyl chloride Benzyl ethyl sulfide Benzyl iodide Benzyl methyl ketone Benzyl methyl sulfide Bicyclo[4.1.0]heptane Bicyclo[3.1.0]hexane... 

Since thujane contains as ring substituents an isopropyl group as well as a methyl group, the name "northujane (see Appendix D) does not conform to the terpene traditional definition of nor. The bicyclo plan name, that is bicyclo[23.1.0 ]hexane, is therefore recommended for the name of the parent ring structure of thujane, the fourth fundamental type of bicyclic terpenes. 

Thujane Sabina ne Tanacetane l-IaopropyM-methyl O bicyclo Q3.1.0 hexane Thujane... 

To a solution of 5-hydroxy-7-oxa-bicyclo[4.1.0]hept-3-ene-3-carboxylic acid methyl ester (4 g, 23.5 mmol) in CH2CI2 (100 ml) was added N,N -diisopropylethylamine (12.3 ml, 70.5 mmol) followed by chloromethyl methyl ether (3.6 ml, 47 mmol, distilled from tech, grade). The solution was refluxed for 3.5 h and the solvent was evaporated. The residue was partitioned between ethyl acetate (200 ml) and water (200 ml). The aqueous phase was extracted with ethyl acetate (100 ml). The combined organic extracts were washed with saturated NaCI (100 ml), dried (MgS04), filtered, and evaporated to afford 4.9 g of a solid residue of 5-methoxymethoxy-7-oxa-bicyclo[4.1.0]hept-3-ene-3-carboxylic acid methyl ester which was of suitable purity to use directly in the next step melting point 62°-65°C (crude) melting point 64°-66°C (diethyl ether/hexane). 

On the other hand, cation formation by decarboxylation of an acyloxonium cation RC02+ is supported by the partial stereospecificity observed in the electrolysis of cis- and trans-bicyclo [3.1.0] hexane-3-carboxylic acid 2°5 and the electrocyclic ring opening in the anodic oxidation of 3-methyl-2-phenylcyclopro-panecarboxylate (22, 23) to cyclopropyl methyl ether (24, 25) and allylic ethers (26, 27) (Eq. (97)) 206). 

CsHjo Cyclohexene, methylcyclopentene, methylene cyclopentane, bicyclo--[3.1.0]-hexane, 2-methyl-1, 4-pentadiene 16.0-18.1 g, m, p 927... 

As shown in Equation (42), the cycloadditions of alkylidene malonates and their derivatives enable selective synthesis of both [2 + 2]- and [2 + 3]-adducts by a proper choice of reaction temperature.167,168 Methyl propiolate undergoes [2 + 2]-cycloaddition predominantly. Use of excess allyltriisopropylsilane induces double [2 + 21-cycloaddition to methyl propiolate, forming a bicyclo[2.2.0]hexane.1 7 The [2 + 2]-cycloadditions of (E)- and (Z)-crotylsilanes proceed stereospecifically. 

Dauben and coworkers observed unusual rate accelerations and ring-expansion rearrangements in the solvolysis of bicyclo[2.2.0]hexane-l-methyl / -nitrobenzoate, in agreement with Winstein s proposed nonclassical cyclobutylmethyl cations (Figure 3). ° Thus, the rate of the solvolysis of bicyclo[2.2.0]hexane-l-methyl p-nitrobenzoate is 7 x 10 times faster than that of the corresponding extrapolated rate for neopentyl derivative. The lack of scrambling of the label in the solvolysis of the 0-labeled... 

Figure 3. Products of solvolysis of bicyclo[2.2.0] hexane-1-methyl p-nitrobenzoate.

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