skeleton, 1,4-dihydro-1,4-epoxy-7H-benzocyclohepten-7-ones have been synthesized by the cycloaddition reaction of 4,5-dehydrotropone with furans and their intramolecular π–π interactions and acid-catalyzedrearrangement to 1-hydroxy-7H-benzocyclohepten-7-ones have been studied.
The reactions of 4,5-dehydrotropone () with several 1-morpholino-1-cycloalkenes, the first examples of [2+2]cycloadditionreactions of , are described and some spectral characteristics of [2+2]cycloadducts obtained are discussed.
A series of tropylium ions incorporated into bicyclo[2.2.1]heptane skeleton having exo-methylene π-system, 1,2,3,4-tetrahydro-1,4-ethylidenebenzotropylium salts, has been synthesized and their charge-transfer interaction and the thermodynamic stability have been examined.
4,5-Dehydrotropone reacted with 4-phenyl-, 5-methyl-4-phenyl-, and 2,5-dimemyl-4-phenyl-oxazol to give, involving facile loss of benzonitrile from the corresponding Diels-Alder adducts, furo-[3,4-d]tropone and its 1-methyl and 1,3-dimethyl derivative, respectively. Protonation of furo[3,4-d]- tropones yielded delocalized 6-hydroxy-3-oxaazulenium ions.