Yaacov Amiel

Alicyclic studies—XI: Attempted syntheses of 5:6-benzazulene and benzheptalenes

Abstract 1-Benzoylcyclopentene was used as starting material in an alicyclic approach towards the synthesis of 5:6-benzazulene. Bromination-dehydrobromination of the intermediate trans -1:2:3:4:9:10 hexahydrobenzazulene afforded a dibromo- and tetrabromo-derivative of 5:6-benzazulene. The bromination-dehydrobromination method is not feasible for the dehydrogenation of hydrobenz-heptalenes to the as yet unknown benzheptalene system.

Alicyclic studies—XII: An alicyclic synthesis of 2:3,6:7-dibenzotropone

Abstract trans -2-Benzylcyclohexylacetic acid was cyclised with polyphosphoric acid to give trans -2:3-benzo-5:6-cyclohexanocycloheptanone. Reduction to the corresponding alcohol followed by dehydration and dehydrogenation afforded 2:3,6:7-dibenzocyclohepta-3:4:6-triene, which was oxidized with selenium dioxide to 2:3,6:7-dibenzotropone.