Cyclododecene-9-dicarboxylic acid

Cyclododeca- tfiene-1,5,9 PdIJHI/Ia Cy clododeca-5,9-dicarboxylic acid + cyclododecene-9-dicarboxylic acid-1,5 [471]... 

Some novel bicyclic pyrylium salts arise when a dicarboxylic acid derivative is used. For example, although decanedioyl chloride did not diacylate isobutene, possibly because of strain inherent in the expected product, 1,12-dodecanedioyl chloride gave a very low yield of the pyrylium salt (658) (62T1079). A dilute solution of the reactants in nitromethane was used in order to favour the intramolecular reaction. In a similar vein, a macrocyclic alkene, such as cyclododecene, undergoes diacylation to the bicyclic salt (659) (68TL4643), whilst... 

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