Basketene

Basketene (IUPAC name: pentacyclo[4.4.0.0^2,5.0^3,8.0^4,7]dec-9-ene^[1]) is an organic compound with the formula C₁₀H₁₀. It is a polycyclic alkene and the dehydrogenated version of basketane, which was named for its structural similarity to a basket. Due to its hydrocarbon composition and unique structure, the chemical compound is of considerable interest to those examining energy surfaces of these (CH)₁₀ cage molecules and what possible factors influence their minima.^[2] Additionally, the complex structure of this compound has intrigued researchers studying the chemistry of highly strained ring systems .^[3] Basketene and its family of derivatives also have important chemical and physical properties. These molecules all tend to have a high standard enthalpy of formation, combined with their high density, leading to possible uses in explosives.^[4]

Basketene

Names
Preferred IUPAC name Pentacyclo[4.4.0.02,5.03,8.04,7]dec-9-ene
Other names Bishomocubene
Identifiers
CAS Number	5603-34-9 Y
3D model (JSmol)	Interactive image
ChemSpider	122156 Y
PubChem CID	138538
CompTox Dashboard (EPA)	DTXSID30971411
InChI InChI=1S/C10H10/c1-2-4-7-5-3(1)6-8(4)10(7)9(5)6/h1-10H Key: LXQOIQYQFRKBLV-UHFFFAOYSA-N InChI=1/C10H10/c1-2-4-7-5-3(1)6-8(4)10(7)9(5)6/h1-10H
SMILES C2=CC5C1C4C3C1C2C3C45
Properties
Chemical formula	C10H10
Molar mass	130.186 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Synthesis

Basketene has been synthesized as follows. First cyclooctatetraene (1) undergoes thermal, electrocyclic isomerization (to 2), followed by a Diels–Alder reaction with maleic anhydride (3). [2 + 2] photochemical cycloaddition (4 to 5) closes the cage structure, which sodium carbonate hydrolyzes (to 6); lead(IV) acetate in pyridine then decarboxylates oxidatively to basketene (7).^[5]

Reactions

Basketene and other cage molecules are important for discovering and testing new concepts of bonding and reactivity.^[4] Oxidizing basketene with osmium tetroxide selectively cleaves the alkene to two carboxylic acid groups; ketonization then gives a cubane precursor.^[6]

Basketene also undergoes a number of different rearrangements.

Rearrangements

Heating Basketene alone produces Nenitzescu’s Hydrocarbon. The reaction proceeds through a reverse Diels-Alder intermediate in order to give 8 at 110 ˚C. From 8, a 3,3 shift occurs to give Nenitzescu's hydrocarbon (9).^[2]

The intermediate 8 can be captured by trapping it as a 1:1 adduct with maleic anhydride.^{[citation needed]}

Basketene can also undergo the following thermal and photochemical rearrangement reactions. The photo-induced conrotary opening of 8 gives cis,cis,trans-cyclooctatriene (10). Furthermore, the photo-rearrangement of 10 provides the derivative 11. 11 will undergo a direct photochemical (2+2) cyclization closure to 12.^{[citation needed]}

Basktene also rearranges into snoutene when in solution with Silver nitrate^[1]