{{Chembox | ImageFileL1 = Basketane-2D-skeletal-bold.png | ImageSizeL1 = 120px | ImageFileR1 = Basketane-3D-balls.png | ImageSizeR1 = 150px | PIN = Pentacyclo[4.4.0.0<sup>2,5</sup>.0<sup>3,8</sup>.0<sup>4,7</sup>]decane | OtherNames = |Section1={{Chembox Identifiers | CASNo = 5603-27-0 | PubChem = 12496332 | ChemSpiderID = 16736517 | SMILES = C2CC5C1C4C3C1C2C3C45 | InChI = 1/C10H12/c1-2-4-7-5-3(1)6-8(4)10(7)9(5)6/h3-10H,1-2H2 | InChIKey = QKWLQWFMFQOKET-UHFFFAOYAB | StdInChI = 1S/C10H12/c1-2-4-7-5-3(1)6-8(4)10(7)9(5)6/h3-10H,1-2H2 | StdInChIKey = QKWLQWFMFQOKET-UHFFFAOYSA-N }} |Section2={{Chembox Properties | C=10 | H=12 | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = }} |Section3={{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }}
'''Basketane''' is a polycyclic alkane with the chemical formula C<sub>10</sub>H<sub>12</sub>. The name is taken from its structural similarity to a basket shape. Basketane was first synthesized in '''1966''', independently<ref>{{ cite journal | journal = Chem. Rev. | year = 1989 | volume = 89 | issue = 5 | pages = 1011–1033 | doi = 10.1021/cr00095a004 | first1= A. P.|last1= Marchand | title = Synthesis and chemistry of homocubanes, bishomocubanes, and trishomocubanes }}</ref> by Masamune<ref name="masamune">{{ cite journal | journal = Tetrahedron Lett. | volume = 7 | issue = 10 | year = 1966 | pages = 1017–1021 | first1= S. |last1=Masamune|first2= H. |last2=Cuts|first3= M. G.|last3= Hogben | doi = 10.1016/S0040-4039(00)70232-2 | title = Strained systems. VII. Pentacyclo[4.2.2.0<sup>2,5</sup>.0<sup>3,8</sup>.0<sup>4,7</sup>]deca-9-ene, basketene. }}</ref> and Dauben and Whalen.<ref>{{ cite journal | journal = Tetrahedron Lett. | volume = 7 | issue = 31 | year = 1966 | pages = 3743–3750 | first1= W. G.|last1= Dauben|first2= D. L.|last2= Whalen | title = Pentacyclo[4.4.0.0<sup>2,5</sup>.0<sup>3,8</sup>.0<sup>4,7</sup>]decane and pentacyclo[4.3.0.0<sup>2,5</sup>.0<sup>3,8</sup>.0<sup>4,7</sup>]nonane | doi = 10.1016/S0040-4039(01)99958-7 }}</ref>
== Nomenclature == Some compounds are named for objects seen in everyday life.<ref name=":0">{{Cite journal|last=Vicens|first=Jacques|date=2007-07-26|title=Aesthetics in chemistry|url=http://link.springer.com/10.1007/s10847-006-9161-7|journal=Journal of Inclusion Phenomena and Macrocyclic Chemistry|language=en|volume=58|issue=3–4|pages=327–328|doi=10.1007/s10847-006-9161-7|s2cid=94479873|issn=0923-0750|url-access=subscription}}</ref> Cubane, housane, and basketane were named accordingly.
== Synthesis == One synthesis of basketane begins with a Diels–Alder reaction between cyclooctatetraene ('''1''') and maleic anhydride ('''2'''), giving the polycyclic anhydride '''3''', which photoisomerizes in acetone via an intramolecular cyclization to give '''4''' at a 40% yield. Hydrolysis of the anhydride followed by treatment with lead tetraacetate affords the unsaturated basketene ('''5'''), which is then hydrogenated to basketane ('''6''').<ref name="masamune"/>
:Image:Synthesis_Basketan.svg
An alternative synthetic route with better overall yield uses 1,4-benzoquinone and cyclohexa-1,3-diene as starting materials. 1,4-Benzoquinone ('''1''') is first converted to 2,5-dibromo-1,4-benzoquinone ('''2'''), which reacts in a Diels–Alder reaction with cyclohexa-1,3-diene ('''3''') to form the polycyclic diketone '''4'''. This diketone photoisomerizes to 1,6-dibromopentacyclo[6.4.0.0<sup>3,6</sup>.0<sup>4,12</sup>.0<sup>5,9</sup>]dodeca-2,7-dione ('''5'''), which undergoes a pseudo-Favorskii rearrangement in a 25% aqueous solution of sodium hydroxide, giving the dicarboxylic acid '''6'''. The acid is decarboxylated with a modified Hunsdiecker reaction to a dibromide '''7''', which is reductively debrominated with tributyltin hydride to basketane ('''8''') at a 11% yield relative to the starting material cyclohexa-1,3-diene.<ref>{{Cite journal |last1=Gassman |first1=Paul G. |last2=Yamaguchi |first2=Ryohei |date=1978 |title=1,8-Bishomocubane |url=https://pubs.acs.org/doi/abs/10.1021/jo00418a028 |journal=The Journal of Organic Chemistry |language=en |volume=43 |issue=24 |pages=4654–4656 |doi=10.1021/jo00418a028 |issn=0022-3263|url-access=subscription }}</ref>
:Image:Synthesis_Basketane_(2).svg
A 1994 synthesis starts with homocubanone, a cubane derivative, forming basketane via the basketyl radical. The synthesis functions by forcing cubane rings to be opened up via structural strain to create the chemical bonds necessary for this rigid molecule.<ref>{{Cite journal|last1=Binmore|first1=Gavin T.|last2=Della|first2=Ernest W.|last3=Elsey|first3=Gordon M.|last4=Head|first4=Nicholas J.|last5=Walton|first5=John C.|date=April 1994|title=Homolytic Reactions of Homocubane and Basketane: Rearrangement of the 9-Basketyl Radical by Multiple .beta.-Scissions|url=http://dx.doi.org/10.1021/ja00086a009|journal=Journal of the American Chemical Society|volume=116|issue=7|pages=2759–2766|doi=10.1021/ja00086a009|issn=0002-7863|url-access=subscription}}</ref> This method is known as ring expansion where one part of two conjoined ringed are opened and rearranged to remove barriers between the two ring systems.<ref name=":1">{{Cite journal|doi=10.1021/jo702164r |title=Ring Opening versus Ring Expansion in Rearrangement of Bicyclic Cyclobutylcarbinyl Radicals |date=2008 |last1=Shi |first1=Jing |last2=Chong |first2=Sha-Sha |last3=Fu |first3=Yao |last4=Guo |first4=Qing-Xiang |last5=Liu |first5=Lei |journal=The Journal of Organic Chemistry |volume=73 |issue=3 |pages=974–982 |pmid=18179235 |url=https://resolver.caltech.edu/CaltechAUTHORS:20210902-233952044 }}</ref>Cyclobutylmethyl radicals that rearrange and open into structures such as basketane and cubane are favorable rearrangements with free energy barriers around 0.3 kcal/mol.<ref>{{Cite journal |last1=Shi |first1=Jing |last2=Chong |first2=Sha-Sha |last3=Fu |first3=Yao |last4=Guo |first4=Qing-Xiang |last5=Liu |first5=Lei |date=2008-02-01 |title=Ring Opening versus Ring Expansion in Rearrangement of Bicyclic Cyclobutylcarbinyl Radicals |url=https://pubs.acs.org/doi/10.1021/jo702164r |journal=The Journal of Organic Chemistry |language=en |volume=73 |issue=3 |pages=974–982 |doi=10.1021/jo702164r |pmid=18179235 |issn=0022-3263|url-access=subscription }}</ref>
== Properties and reactions== The C-C-C and H-C-C bond angles in basketane and several other cages deviate from 109.5 degrees, i.e., they are strained rings.<ref name=":2">{{Cite journal|last=Marchand|first=Alan P.|date=1989-07-01|title=Synthesis and chemistry of homocubanes, bishomocubanes, and trishomocubanes|url=https://pubs.acs.org/doi/abs/10.1021/cr00095a004|journal=Chemical Reviews|volume=89|issue=5|pages=1011–1033|doi=10.1021/cr00095a004|issn=0009-2665|url-access=subscription}}</ref> The strain energy is reflected in high heat of combustion.<ref name=":2" />
===Metal-catalyzed rearrangements=== Transition metals catalyze the valence isomerization of basketane and substituted derivatives. Silver perchlorate catalyzes its isomerization to the compound snoutane.
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Other transition metals catalyze the formation of a snoutane derivative with a tricyclic diene. The ratio of the products depends on the nature of the catalyst used and the substitutions on the basketane.<ref>{{Cite journal |last1=Paquette |first1=Leo A. |last2=Boggs |first2=Roger A. |last3=Farnham |first3=William B. |last4=Beckley |first4=Ronald S. |date=1975 |title=Silver(I) ion catalyzed rearrangements of strained .sigma. bonds. XXIX. Influence of structural features on the course of transition metal catalyzed 1,8-bishomocubane rearrangements |url=https://pubs.acs.org/doi/abs/10.1021/ja00838a026 |journal=Journal of the American Chemical Society |language=en |volume=97 |issue=5 |pages=1112–1118 |doi=10.1021/ja00838a026 |issn=0002-7863|url-access=subscription }}</ref>
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Basketane absorbs an equivalent amount of hydrogen gas in the presence of palladium on carbon, After some initial confusion, it was shown that the C3-C4 bond is hydrogenolyzed to give the dihydrobasketane tetracyclo[4.4.0.0<sup>2,5</sup>.0<sup>3,8</sup>]decane.<ref>{{Cite journal |last1=Andre Sasaki |first1=N. |last2=Zunker |first2=Reinhard |last3=Musso |first3=Hans |date=1973 |title=Welche C–C‐Bindung wird bei der Hydrierung von Basketanderivaten geöffnet? |url=https://onlinelibrary.wiley.com/doi/10.1002/cber.19731060930 |journal=Chemische Berichte |language=en |volume=106 |issue=9 |pages=2992–3000 |doi=10.1002/cber.19731060930 |issn=0009-2940|url-access=subscription }}</ref> Further hydrogenation cleaves the C5-C6 bond to give the hydrocarbon twistane.<ref>{{Cite journal |last=Musso |first=Hans |date=1975 |title=Hydrogenolyse kleiner Kohlenstoffringe, II. Über die Hydrierung von Basketan‐ und Snoutanderivaten |url=https://onlinelibrary.wiley.com/doi/10.1002/cber.19751080143 |journal=Chemische Berichte |language=en |volume=108 |issue=1 |pages=337–356 |doi=10.1002/cber.19751080143 |issn=0009-2940|url-access=subscription }}</ref>
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==See also== *Cubane *List of chemical compounds with unusual names
==References== {{reflist}}
==Further reading== * {{ cite journal | journal = J. Am. Chem. Soc. | year = 1994 | volume = 116 | issue = 7 | pages = 2759–2766 | first1= Gavin T.|last1= Binmore|first2= Ernest W.|last2= Della|first3=G. M.|last3= Elsey|first4= N. J.|last4= Head|first5= J. C.|last5= Walton | doi = 10.1021/ja00086a009 | title = Homolytic Reactions of Homocubane and Basketane: Rearrangement of the 9-Basketyl Radical by Multiple β-Scissions }} {{Hydrocarbons}} Category:Cyclobutanes Category:Substances discovered in the 1960s Category:Pentacyclic compounds Category:Cyclohexanes Category:Polycyclic nonaromatic hydrocarbons
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