Basketene

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]

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.

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]

Wikimedia Commons has media related to Basketene.