Bicyclo heptane, 1-chloro

Reaction with l-chloro-2-methylcyclohexene (1). This vinyl halide reacts with phenyllithium (5 equiv.) to give the bicyclo[4.1.0]heptane (2) in 90% yield. The paper presents evidence for the intermediacy of the cyclopropene a. Other organo-lithium reagents react in the same way, but yields are lower, 47% in the case of CHjLi. 

SYNS BORNANE, 2-CHLORO-, endo- 2-CHLORO-CAMPHANE BICYCLO(2,2,l)HEPTANE, 2-CHLORO-1,7,7-TRIMETHYL-, endo- BORNYL CHLORIDE TERPENE HYDROCHLORIDE TURPENTINE CAMPHOR endo-2-CHLORO-l,7,7-TRIMETHYU BICYCLO(2.2.1)HEPTANE... 

As expected, delocalizing substituents such as carbomethoxyl and cyano should decrease the barrier to inversion and perhaps may even convert the rapidly inverting g radical to a linear n radical. The net result should be a loss of configuration. Ando and coworkers have shown this to be the case in the tri-n-butyltin hydride reduction of the isomeric exo- (38) and n io-7-chloro-7-carbomethoxybicyclo[4.1.0]heptane (39). Both isomers gave the same (7 93) ratio of exo- (40) and emio-methyl bicyclo[4.1.0]heptane-7-carboxylate (41). 

A number of bromocyclopropanes which also contain an electrophilic center in the molecule, undergo intramolecular substitution under the right conditions. When l-bromo-7-(3-chloro-propyl)tricyclo[4.1.0.0 ]heptane was reacted with butyllithium, tetracyclo[5.3.0.0 .0 ]de-cane (10) was obtained in 52% yield.Under similar conditions several substituted 7-bromo-bicyclo[4.1.0]heptene anti-epoxides and other epoxides were converted to polycyclic alcohols which result from intramolecular attack of the cyclopropyl anion on the oxirane ring. ... 

When 7,7-dichlorobicyclo[4.1.0]heptane was reacted with potassium tert-butoxide in dimethyl sulfoxide in the presence of a C-H acid, elimination of hydrogen chloride, giving 7-chloro-bicyclo[4.1.0]hept-l(7)-ene, was followed by addition to the cyclopropene of the carbanion obtained from the C-H acid. The course of reaction was sensitive to several factors, among which the C-H acid employed was of significant importance. -Thus, when diethyl mal-onate was used several benzene derivatives were obtained and alkyl-substituted cyclopropanes were afforded, but in low yields. However, dehydrochlorination in the presence of 2-phenyl-propanonitrile gave 2-(bicyclo[4.1.0]hept-5-en-l-yl)-2-phenylpropanonitrile (1) and minor amounts of 2-ethyltoluene. ... 

Cyclopropylideneacetates also undergo [4-1-2] cycloadditions to yield spiro[2.5]octene derivatives. The relative Diels-Alder reactivities of 2-heteroatom-substituted 2-cyclo-propylideneacetates, as determined by competition experiments with furan to give 7-oxa-bicyclo[2.2.1]heptanes 18, have been studied. The 2-chloro and 2-bromo derivatives were equally reactive and underwent cycloaddition ca. 16 times faster than methyl acrylate, which in turn is far more reactive than methyl 2-chloro-3,3-dimethylacrylate. Selected examples of [4-1-2] cycloadditions are given in Table 4, for further examples see refs 10, 22, 44 and 45. 

Ring expansion of the substituted bicyclo[4.1.0]heptanes 8, formed by addition of chloromethyl-carbene to silyl enol ethers, was accomplished almost equally effectively by refluxing in toluene, or by heating in methanol containing triethylamine. In each case, the crude mixture of cis- and /rani-7-chloro-7-methylbicyclo[4.1. Ojheptanes 8 was used, although it was observed that the traui-isomers, with the chlorine and trimethylsiloxy substituents tram to each other, rearranged more rapidly. 

Bicyclo[4.1,0 heptane 7-Chloro-7-methyl-l-(4-trifluoro-methyl-phenyl)- 1437 C. H. aNOjS Cyclopropane... 

Compared to their carbon bioisosteres, silicon-containing molecules are more sensitive to hydrolysis and to nucleophilic attack in general, even when located in the center of a quaternary structure, the risk exists that the silicon atom will be attacked. Thus, l-chloro-l-sila-bicyclo-(2,2,l)-heptane can still be hydrolyzed by an attack on the vacant d orbital this attack is lateral and therefore possible even in the cases where the corresponding carbon derivative would have been inert toward a Sn2 reaction (Figure 15.69). 

A similar preference for cis- or emfo-products is generally observed in the reactions of thermally generated chloro(trichloroethenyl)carbene with a large variety of olefins (see Vol. E 19b, p 740)11. The alkynyl-substituted earbene 4 obtained by photolysis of 5-bromoethynyl-3,3-dimethyl-3//-pyrazole adds exo selectively to 3-cyclohexenone to give an 80 20 mixture of 7-bromo-7-(4-methyl-3-penten-l-ynyl)bicyclo[4.1.0]heptan-3-one (5/6)12. The reaction of chlorophenylcarbene and cyclohexene affords 7-chloro-7-phenylbicyclo[4.1.0]heptane with moderate endo preference (see Vol. E19b, p984), i. 

Trimethylsilyl)carbene and (trimethylstannyl)carbene can be generated from the corresponding chloro precursors by a-elimination employing lithium 2,2,6,6-tetramethylpiperidide as base6. Their reactions with cyclohexene proceed with very high exo selectivities giving 7-(trimethylsilyl)bicyclo[4.1.0]heptane (9) and 7-(trimethylstannyl)bicyclo[4.1.0]heptane (10), however, the chemical yields are rather low. 

Cbloro-d-camphor. 3-Chloro-l,7,7-trimethyl-bicyclo[2.2.I]heptan 2 one 3-chloro-d-2-bornanone. C (-... 

SR144528 - A-[l(5)-Endo-l,3,3-trimethyl bicyclo [2.2.1] heptan-2-yl]-5-(4-chloro-3-methyl-phenyl)-1 -(4-methylbenzyl)-pyrazole-3-carboxamide FBS - Fetal bovine serum... 

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