Abstract:The ionic chlorination of 9,10-dihydro-9,10-ethenoanthracene was shown to yield exo-and endo-4-syn-8dichlorodibenzobicyclo[3.2.1 ]octadiene as the sole reaction products. The less stable of these isomers was the preponderant product. The structure proofs of these addition-rearrangement reaction products and some of their chemistry are discussed. Ionic chlorination of 9,10-dihydro-9,10-ethenoanthracene (I) in carbon tetrachloride gave two isomeric dichlorides, A and B, neither of which were cisor trans-11,12-di… Show more
“…However, 1,3-diphenyl-1-propanol (7) gave up to 34% cylization product, 1-phenylindan, as well as the main product, a higher boiling one which we believe to be the result of intermolecular condensation reactions. 6 The ability of this secondary phenylalkanol to undergo cyclialkylation confirms the idea that a stable carbonium ion intermediate, in this case stabilized by a phenyl group, is required.…”
Section: Resultssupporting
confidence: 57%
“…Upon treatment with sulfuric acid at room temperature, the two tertiary alcohols, 2-methyl-4-phenyl-2butanol (4) and 2-methyl-5-phenyl-2-pentanol (5), gave 1,1-dimethylindan and 1,1-dimethyltetralin, respectively. The secondary alcohol, 5-phenyl-3-pentanol (6), gave 1-methyltetralin. These were the products reported by Roblin,Davidson,and Bogert.3 It should be noted that a hydrogen shift, converting one secondary carbonium ion to another, allows the formation of the tetralin in preference to the indan4 in the last case.…”
Section: Resultsmentioning
confidence: 99%
“…1,1-Dimethylindan (18), 2-methyl-3phenyl-2-butene (82)* " Mole per cent of distillable hydrocarbons based on original phenylalkanol. 6 The percentage composition of various products was calculated by integration of glpc recordings. = Reduction of this mixture by hydrogen and palladium on carbon in ethanol gave nbutylbenzene as the sole product.…”
CYCLIALKYLATIONS OF SOME PHENYLALKANOLS 3571 ratio was detected until the amount of olefin exceeded 10%. Above 10% small differences were noted and the values indicated that the cis alcohol (equatorial OH) was being dehydrated a t a faster rate than the trans alcohol.Control Experiment.--The isolated product obtained from the reaction of methylmagnesium bromide (0.1 M ) with 4-t-butylcyclohexanone (Table I) was dissolved in 10 ml of ether and added to dimethylcadmium or dimethylzinc reagents under the conditions previously described for the reaction of in situ reagents with ketone. After hydrolysis arid work-up, percentages obtained by glpc were unchanged within experimental error.Registry methylzinc, 1, methylmagnesium iodide, methylmagnesium bromide, methyllithium, Ac~owledgment,-we thank the Central university Research Fund (University Of New Hampshire) for partial support.Tertiary 3-and 4-phenylalkanols underwent cyclialkylation readily a t room temperature with sulfuric acid to yield the corresponding indans and tetralins. Primary and (ordinary) secondary 3-phenylalkanols did not undergo cyclialkylation even a t high temperature with phosphoric acid; l,3-diphenyl-l-propanol cyclized readily. 3-P14ethyl-3-phenyl-l-butanol was dehydrated (mainly) by phosphoric acid a t 230°, but some cyclialkylation ocwirred. The requirement of a stable secondary or tertiary carbonium-ion intermediate is implied by these results; in the case of the last example, a l13-phenyl shift provides the required intermediate.
Some time ago Bogert and ~o w o r k e r s~~~investigated the cyclialkylations of some phenylalkanols and related alkenes. They identified their cyclization products by means of qualitative elemental analyses, comparison of physical constants, and characterization, of oxidation products. Since such identification methods are qualitative a t best and probably liable to failure in detecting minor components, we decided to reinvestigate some of the reported results, applying modern instrumental methods of separation and identification. Some of the experiments are repetitions of cyclialkylations reported previously, 2 , 3 but others are new ones designed to provide more insight into the mechanisms of these reactions.
Results and DiscussionThe conditions and results of our cyclization experiments are summarinied in the accompanying Table I. 3-Phenyl-1-propanol (1) and 4-phenyl-1-butanol ( 2 ) were reported by Bogert and Davidson2 to yield polymer and pure tetralin, respectively, upon treatment with phosphoric acid at high temperature. We obtained a product from the former that was shown to contain a trace of indan and a little n-propylbenzene, but the major constituents were the three isomeric phenylpropenes resulting from normal dehydration. Confirmatory evidence for the structure of the latter isomers was obtained by catalytic reduction which converted them to n-propylbenxene, The product from 2 was found to consist of tetralin (80%) and three lower boiling unidentified products (20%).4-Phenyl-2-butanol (3) was report...
“…However, 1,3-diphenyl-1-propanol (7) gave up to 34% cylization product, 1-phenylindan, as well as the main product, a higher boiling one which we believe to be the result of intermolecular condensation reactions. 6 The ability of this secondary phenylalkanol to undergo cyclialkylation confirms the idea that a stable carbonium ion intermediate, in this case stabilized by a phenyl group, is required.…”
Section: Resultssupporting
confidence: 57%
“…Upon treatment with sulfuric acid at room temperature, the two tertiary alcohols, 2-methyl-4-phenyl-2butanol (4) and 2-methyl-5-phenyl-2-pentanol (5), gave 1,1-dimethylindan and 1,1-dimethyltetralin, respectively. The secondary alcohol, 5-phenyl-3-pentanol (6), gave 1-methyltetralin. These were the products reported by Roblin,Davidson,and Bogert.3 It should be noted that a hydrogen shift, converting one secondary carbonium ion to another, allows the formation of the tetralin in preference to the indan4 in the last case.…”
Section: Resultsmentioning
confidence: 99%
“…1,1-Dimethylindan (18), 2-methyl-3phenyl-2-butene (82)* " Mole per cent of distillable hydrocarbons based on original phenylalkanol. 6 The percentage composition of various products was calculated by integration of glpc recordings. = Reduction of this mixture by hydrogen and palladium on carbon in ethanol gave nbutylbenzene as the sole product.…”
CYCLIALKYLATIONS OF SOME PHENYLALKANOLS 3571 ratio was detected until the amount of olefin exceeded 10%. Above 10% small differences were noted and the values indicated that the cis alcohol (equatorial OH) was being dehydrated a t a faster rate than the trans alcohol.Control Experiment.--The isolated product obtained from the reaction of methylmagnesium bromide (0.1 M ) with 4-t-butylcyclohexanone (Table I) was dissolved in 10 ml of ether and added to dimethylcadmium or dimethylzinc reagents under the conditions previously described for the reaction of in situ reagents with ketone. After hydrolysis arid work-up, percentages obtained by glpc were unchanged within experimental error.Registry methylzinc, 1, methylmagnesium iodide, methylmagnesium bromide, methyllithium, Ac~owledgment,-we thank the Central university Research Fund (University Of New Hampshire) for partial support.Tertiary 3-and 4-phenylalkanols underwent cyclialkylation readily a t room temperature with sulfuric acid to yield the corresponding indans and tetralins. Primary and (ordinary) secondary 3-phenylalkanols did not undergo cyclialkylation even a t high temperature with phosphoric acid; l,3-diphenyl-l-propanol cyclized readily. 3-P14ethyl-3-phenyl-l-butanol was dehydrated (mainly) by phosphoric acid a t 230°, but some cyclialkylation ocwirred. The requirement of a stable secondary or tertiary carbonium-ion intermediate is implied by these results; in the case of the last example, a l13-phenyl shift provides the required intermediate.
Some time ago Bogert and ~o w o r k e r s~~~investigated the cyclialkylations of some phenylalkanols and related alkenes. They identified their cyclization products by means of qualitative elemental analyses, comparison of physical constants, and characterization, of oxidation products. Since such identification methods are qualitative a t best and probably liable to failure in detecting minor components, we decided to reinvestigate some of the reported results, applying modern instrumental methods of separation and identification. Some of the experiments are repetitions of cyclialkylations reported previously, 2 , 3 but others are new ones designed to provide more insight into the mechanisms of these reactions.
Results and DiscussionThe conditions and results of our cyclization experiments are summarinied in the accompanying Table I. 3-Phenyl-1-propanol (1) and 4-phenyl-1-butanol ( 2 ) were reported by Bogert and Davidson2 to yield polymer and pure tetralin, respectively, upon treatment with phosphoric acid at high temperature. We obtained a product from the former that was shown to contain a trace of indan and a little n-propylbenzene, but the major constituents were the three isomeric phenylpropenes resulting from normal dehydration. Confirmatory evidence for the structure of the latter isomers was obtained by catalytic reduction which converted them to n-propylbenxene, The product from 2 was found to consist of tetralin (80%) and three lower boiling unidentified products (20%).4-Phenyl-2-butanol (3) was report...
“…Direct acid-mediated ring interconversion of bicyclo[2.2.2]octene ( 501 ) was found to give, depending on the reaction conditions, the bicyclooctanol 182 106 or the bicyclo[3.2.1]octene 502 , while performic acid oxidation furnished diol 503 in quantitative yield, a transformation also effective with dibenzobicyclo[2.2.2]octadiene . Similarly, the deamination of bicyclic amines, Hell−Volhard−Zelinsky bromination of bicyclo[2.2.2]octane-2-carboxylic acid, ionic chlorination, and also radical addition of HBr 292 to unsaturated [2.2.2] bridged precursor proceed with isomerization to the corresponding functionalized bicyclo[3.2.1]octane derivatives. …”
Section: Rearrangement Of Polycyclic Intermediatesmentioning
“…Rearranged products have also been observed in the chlorination of dibenzobicyclo[2.2.2]octadiene (142), norbornene (1 36), and benzonorbornadiene (143). Rearranged products have also been observed in the chlorination of dibenzobicyclo[2.2.2]octadiene (142), norbornene (1 36), and benzonorbornadiene (143).…”
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